Does a hobbyist need a bench power supply?

[Rhythmtech]

I'm glad I'm not the only one having trouble finding Mastech manuals online.
But seriously, a Quakko power supply?  I'm still smiling at the name.  Aren't
they another brand of Aoyue?  I've heard of them only in the context of
SMD rework stations.

Personally, I tend to prefer the LED displays over the LCD -- easier
for my eyes to read :-)  If money were no object, I like the
Hameg 7044: http://www.hameg.com/163.0.html

But we're outside of what most hobbyists need, including me!

I suppose it's too much to ask for a power supply manual to contain
schematics these days (the Extech manual does not).


Scott

If you look at the Quakko model number it is very similar to all of Mastech's power supply products, I don't know who the ultimate manufacturer might have actually been. Seems like Rebranding clones is becoming more lucrative than counterfits are. This is worrisome as I don't believe people are unknowingly buying fakes anymore.

[saturation]

It reads good, but consider its size and weight when it occupies your bench.  At those requirements I get confused between going to the switching supply camp.  I should have added that choice to my example:

http://www.mastechpowersupply.com/dc-power-supply/linear-power-supply/mastech-variable-linear-power-supply-30v-10a-hy3010d/prod_11.html

http://www.mastechpowersupply.com/dc-power-supply/switching-power-supply/mastech-power-supply-hy3010ex-30v-10a-over-voltage-over-current-protection/prod_70.html

So their sale price is $90 for a 0-30V 0-3amp supply.
For about $170, what do you think about their 3 output supply:

http://mastechpowersupply.com/dc-power-supply/linear-power-supply/mastech-linear-dc-power-supply-30v-3a-hy3003f-3-triple-outputs/prod_7.html

Looks like two of the $90 supplies put together with a 5v supply thrown in
for less than 2X the cost.

Scott

[saturation]

Yes, I think there are other brand names as well.  Here's the parent website, it looks like their principle is Mastech.

http://www.mastech.com.cn/html/en/products-dc-1.htm

A good news for skeptics, Instek's low end linear look like rebadged or upgraded Mastech, including the same model numbers, so one could say Instek's management has some faith in this product line:

http://www.gwinstek.com/en/product/productdetail.aspx?pid=38&mid=53&id=128

I'm glad I'm not the only one having trouble finding Mastech manuals online.
But seriously, a Quakko power supply?  I'm still smiling at the name.  Aren't
they another brand of Aoyue?  I've heard of them only in the context of
SMD rework stations.

Personally, I tend to prefer the LED displays over the LCD -- easier
for my eyes to read :-)  If money were no object, I like the
Hameg 7044: http://www.hameg.com/163.0.html

But we're outside of what most hobbyists need, including me!

I suppose it's too much to ask for a power supply manual to contain
schematics these days (the Extech manual does not).


Scott

If you look at the Quakko model number it is very similar to all of Mastech's power supply products, I don't know who the ultimate manufacturer might have actually been. Seems like Rebranding clones is becoming more lucrative than counterfits are. This is worrisome as I don't believe people are unknowingly buying fakes anymore.

[Rhythmtech]

Instek may impose their quality control standards on the product line which they sell under their name, which would be good. Sometimes, this is not transferred to the manufacturer's QC though for products manufactured under their brand. So even if it is the same product it does not mean that their are equal. 

Given it is the low end they are probably the same units since additional development cost would probably negate the production costs savings. Presumably they have tested the unit to verify it is up to their spec. Assuming Mastech's is not a complete piece of junk is fair.  Although, buying Mastech then using GWInstek's support infrastructure to save a couple bucks would not sit well with me. I need my equipment manufacturer's to be there for me when I need them to be and not out of business or without documentation to remain competitive.

[cybergibbons]

The re-branding thing gets deeply confusing. You're never quite sure if something with the same specs and front panel is actually the same beneath the skin, or just someone very, very good at copying a product. We got some DeWalt cordless power tools from the Far East once, and even the cast aluminium parts were spot on - the only problem was the cheap gear boxes, motors and batteries!

For example, Farnell sells a number of different items as "Tenma". Sometimes they actually re-badge them (both physically and in manuals), other times they just sell the original brand - loads of Tenma multimeters are just Uni-T ones. It's quite weird.

[Rhythmtech]

The re-branding thing gets deeply confusing. You're never quite sure if something with the same specs and front panel is actually the same beneath the skin, or just someone very, very good at copying a product. We got some DeWalt cordless power tools from the Far East once, and even the cast aluminium parts were spot on - the only problem was the cheap gear boxes, motors and batteries!

For example, Farnell sells a number of different items as "Tenma". Sometimes they actually re-badge them (both physically and in manuals), other times they just sell the original brand - loads of Tenma multimeters are just Uni-T ones. It's quite weird.

Many clone products are made on the same equipment as the originals. Discarded dies, molds, etc... are copied or repaired and reused. I can imaging sloppy gears coming from worn dies out of spec. I've heard more than one story of the great savings of chinese die manufacturers as they recoup profits by making a second set of your dies without letting you know, then selling them down the street.  Ghost shifts runs can be on the same equipment the originals were currently being manufactured on save for the quality control on materials used to manufacture the parts or cheaper filler blended or substituted.

Here's a great story - BunnieStudios Chumby On microSD Problems

Okay to unhijack the thread....

I think defining how the power supply will be used will tell us what we need. 

For me, I rarely ever run in to an instance of needing more than +/- 15V at more then 2 amps for the electronics I assemble as prototypes.  This solidly puts me in the middle of the voltage/current range. Servos, stepper motors, nixie tube power and the like generally I would either purchase a powered control or build a separate power circuit. I would like programmable capabilities, because I enjoy integrating equipment and turning multiple systems into one.  Regulation is usually obtained by a linear regulator on my finished circuits with regulators like a LM7805 or LM317, so any bench power supply with regulation of ~0.1% is good enough, which most Mastechs we've looked at do ~0.01%.  I probably will only use it 1 to 10 times a week for 1 - 4 hours each time, and nobody will lose thousands of dollars for ever minute it is down if it breaks, so a Mastech would probably fit my needs well enough for everything I am going to want to use it for.   


 

[saturation]

Yet another 'clone':

Yes, I think there are other brand names as well.  Here's the parent website, it looks like their principle is Mastech.

http://www.mastech.com.cn/html/en/products-dc-1.htm

A good news for skeptics, Instek's low end linear look like rebadged or upgraded Mastech, including the same model numbers, so one could say Instek's management has some faith in this product line:

http://www.gwinstek.com/en/product/productdetail.aspx?pid=38&mid=53&id=128

I'm glad I'm not the only one having trouble finding Mastech manuals online.
But seriously, a Quakko power supply?  I'm still smiling at the name.  Aren't
they another brand of Aoyue?  I've heard of them only in the context of
SMD rework stations.

Personally, I tend to prefer the LED displays over the LCD -- easier
for my eyes to read :-)  If money were no object, I like the
Hameg 7044: http://www.hameg.com/163.0.html

But we're outside of what most hobbyists need, including me!

I suppose it's too much to ask for a power supply manual to contain
schematics these days (the Extech manual does not).


Scott

If you look at the Quakko model number it is very similar to all of Mastech's power supply products, I don't know who the ultimate manufacturer might have actually been. Seems like Rebranding clones is becoming more lucrative than counterfits are. This is worrisome as I don't believe people are unknowingly buying fakes anymore.

[comox]

I'm an IT professional by trade, and an electronics hobbyist by, um, hobby...  I'm also weird as I have 4 benchtop PSUs:

1x TTi 302T triple-output bench top power supply (backup, in closet)



2x TTi laboratory-grade QL355TP bench top power supplies.  Yup 2 of ‘em.



1x Agilent 6811b AC power supply and analyzer, which I control from a PC using a USB-to-GPIB adapter.



The Agilent 6811b is a dangerous piece of kit and produces deadly voltage levels, but I use it all the time as I work with AC and power supplies.  In fairness, the Agilent 6811b is on the floor.

The QL355TP is a great, but produces some fan noise.  I love the TTI power supplies, and I believe that they are made in Britain.

Proper bench top PSUs will give you control over both voltage and current, which can be handy during the design phase.  For example, let’s say you are designing a circuit that you wish to power from a battery.  During the design phase, you would dial in the voltage and power limits of the battery into the PSU as to ensure that your circuit will operate within the power limits of the chosen battery.  A PSU with current control would allow you to limit the amount of power available to the circuit under development allowing you to ensure that power is not exceeded.  A good PSU would display in real time the current being consumed by the circuit.  All good stuff.

[logictom]

I still need to either buy or build a power supply, I keep changing my mind if I should buy or build.
The main thing putting me off building is finding a good case and making the thing look half decent. Whilst buying a supply is less educational, you get less control over the specs and for anything with more than one output they seem to be £120+

This is the most reasonable single output one I can find http://www.maplin.co.uk/Module.aspx?ModuleNo=219129&j=true the rather limited datasheet but is it cheap because it's a load of garbage?

[Time]

The Agilent 6811b is a dangerous piece of kit and produces deadly voltage levels, but I use it all the time as I work with AC and power supplies.  In fairness, the Agilent 6811b is on the floor.

You must be a very successful IT professional to own a serious piece of equipment like this for hobby reasons.   

[slburris]

So I asked support@mastechpowersupply.com for a schematic of the HY3003F-3.

They didn't have that, but sent me a schematic of the next one up in the series,
the HY3005-3.  I haven't studied it in great detail yet, but it give me hope I could
repair one of these if I decide to purchase it.

Note that mastechpowersupply.com is a US distributer, Acifica, Inc.

Scott

[saturation]

I have a link below with additional schematics, they look pretty standard, for those in the linear range.

More importantly, I've also canvassed Amazon feedback from those who have purchased Mastech PSU, and most have been favorable.  Some comments on build quality, only one had a major failure.  Their forum posts may be misleading about quality, since most posts are about tech support issues and complaints, so posts are about damaged units.

I sent a email to them inquring too about schematics and user manuals and pdf, and response was prompt, within the hour, but nothing to send.

Last item I found is their eBay pages:

http://reviews.ebay.com/Mastech-Power-Supply_W0QQugidZ10000000008864448

He has a good rep.

So I asked support@mastechpowersupply.com for a schematic of the HY3003F-3.

They didn't have that, but sent me a schematic of the next one up in the series,
the HY3005-3.  I haven't studied it in great detail yet, but it give me hope I could
repair one of these if I decide to purchase it.

Note that mastechpowersupply.com is a US distributer, Acifica, Inc.

Scott

[saturation]

Nice stuff.  I like your enthusiasm! Care to share why you have 4 bench supplies?

I'm an IT professional by trade, and an electronics hobbyist by, um, hobby...  I'm also weird as I have 4 benchtop PSUs:
...A good PSU would display in real time the current being consumed by the circuit.  All good stuff.

[comox]

I bought the TTi el302tv back in 2007 new for £305 (British pounds, excluding VAT) when I first started playing around with microprocessors.  It is a nice unit, and good for the bench as it has NO fan noise.  However, the analogue dials are easy to bump and thus knock the voltage and/or current limits askew.

I bought the first TTi QL355TP 2 years later, second-hand on eBay (UK) for £530, ex VAT.  I was after a more precise power supply as I was experimenting with charger designs (e.g. phone charger, gadget charger) at the time.  This is a great unit, but produces fan noise.  No risk of knocking the power or current limit settings as it is digital.  This is now my daily use benchtop PSU and the el302tv is in the closet.

I bought the second TTi QL355TP a couple months later for TTi directly, ex demo, for £478.50, ex VAT.  Funny that: was cheaper than eBay, and was in brand-new condition.  I bought it because I am weird and need things I like in 2s.  Not kidding: when I grocery shop, I never buy one of something I like.  Kind of like Obsessive Compulsive Disorder, but stops it at 2.  However, I would like to point out that I have only 1 handheld multimeter, unlike our esteemed video blogging host!

There is no reason that I needed the second QL355TP.  I was sent an ex-demo salesheet from TTi and phoned them to purchase an ex-demo LD300 DC electronic load.  It was sold already so I purchased the QL355TP instead.  As I said, I am weird.

I purchased the Agilent 6811b back in Feb this year as I have been doing a lot of work with AC power switching.  I have been working on a zero-crossing detection circuit for actuating a relay when the AC voltage crosses the zero threshold.  I needed to produce a design that would work "around the world" regardless of line voltage (e.g. 110V US, or 250V in Europe) or line frequency (e.g. 60Hz US or 50Hz Europe) and I therefore needed a special power supply that could output AC voltage at different frequencies.  The 6811b was the answer, and I found a second-hand one on eBay for £1455 ex VAT.  brand new would have been at least £4000.  Had to splurge on an Agilent USB-to-GPIB adapter to control it with the PC, but was worth it.  This is a very cool product, but very dangerous due to the high voltages produced.   Did you know that AC in aircraft operates at 400Hz?

I have been in IT for 20 years, and am burned out with pushing bits around.  I am the same age as Dave and my original love was always electronics.  I re-discovered electronics a few years back, and have put my heart into it.  Dave's videos fill in the theory that I missed a) not studying electronics at uni, and b) not doing it for a living.

I would recommend the Thurlby Thandar (TTi) kit to anyone, as I think it is well engineered.  And heck, it is made in Britain! 

Comox

[cybergibbons]

I've used very similar Agilent gear for testing products to see if they will deal with different voltages and frequencies. Also you can produce glitches and the like, for simulating generator power, or if you are testing a UPS. If I remember correctly it has fairly good control of limits so you can't really break anything by just spinning a dial...

The power in aircraft is 400Hz because you can reduce the size of inductors and transformers I believe.

Anyway, I managed to pick up a GPS-4303 for not much more than the cheap Caltek supply... it seemed like a pricing error at first, but called up, and it isn't ex-demo or anything. Seems like a nice bit of kit - the design does look v. similar to the Caltek shown on rcgroups.com but the construction standard appears to be higher.

[saturation]

A nice unit, CG, and another Instek.  Did you have a particular need for this type of power, or was it just a good unit for price?  It ranges in the $400 US.

The manual is at tequipment, and it reads impressively for a 7kg unit.  Its not explicit but it reads like a switching power supply but with regulation and ripple to rival the best linear supplies.

I've used very similar Agilent gear for testing products to see if they will deal with different voltages and frequencies. Also you can produce glitches and the like, for simulating generator power, or if you are testing a UPS. If I remember correctly it has fairly good control of limits so you can't really break anything by just spinning a dial...

The power in aircraft is 400Hz because you can reduce the size of inductors and transformers I believe.

Anyway, I managed to pick up a GPS-4303 for not much more than the cheap Caltek supply... it seemed like a pricing error at first, but called up, and it isn't ex-demo or anything. Seems like a nice bit of kit - the design does look v. similar to the Caltek shown on rcgroups.com but the construction standard appears to be higher.

[saturation]

A fun story, pretty much in the vein of a lot of enthusiasm here.  I'm sure if you have rechargeable batteries around, they are getting well topped up 

< snip a nice story...>

I would recommend the Thurlby Thandar (TTi) kit to anyone, as I think it is well engineered.  And heck, it is made in Britain! 

Comox

[Kiriakos-GR]

With all this digits on display , I got excited ...  

I have the Kenwood PD3510 laboratory-grade PSU , is there any worthy solutions , so to replace the analog voltage meter , with digits .  (4 or 5 digits resolution) 

I could glue on it the Fluke 87-5    , but I am looking for an "true good" alternative solution.

[NiHaoMike]

To all those that feel the self-built is the best route to go - can a home built supply even compete on cost with a bought one? There's quite a few high value parts in there:
* Transformer
* Case
* Smoothing caps
* Heatsinks
* Panel meters

I just remember the first audio amp I built from a kit (I think it was 150W or so)- the kit itself cost about £50, built and tested at school using a bench power supply. Then I came to casing it, and found that mains lead, fuse, power switch, grommets, terminals, phones all cost a fair bit. Then there was the power supply... cost an absolute fortune!

Surplus/recycled parts can really lower the cost. Especially if your application needs a supply similar to a mass market unit like ATX power supplies. And really oddball power supplies would be cheaper to build.

[cybergibbons]

A nice unit, CG, and another Instek.  Did you have a particular need for this type of power, or was it just a good unit for price?  It ranges in the $400 US.

The manual is at tequipment, and it reads impressively for a 7kg unit.  Its not explicit but it reads like a switching power supply but with regulation and ripple to rival the best linear supplies.

After all of the earlier posts, I was looking for a bench power supply - the RF transmitter/receiver project I am on at the moment needs two independent voltages, one of which I need to vary from 1-12V. It was just cheaper than any other dual rail power supply so I went for it. I can't remember how many 5V wall warts I've frazzled now as well (I have maybe 30 in a box, all old phone chargers).

I do have to admit, I'm pretty happy with it - it seems to perform well. It works up to about 32V/3.2A on each channel. Maybe my only complaint is the single output on/off button - though it does make a satisfying series of clicks as all 4 sets of relays come in and out. I may even try it with a powerful audio amp to see how it copes!

[saturation]

If you are ever inclined to dissect it and see how its made inside, I'd be interested in the quality of their engineering.

A nice unit, CG, and another Instek.  Did you have a particular need for this type of power, or was it just a good unit for price?  It ranges in the $400 US.

The manual is at tequipment, and it reads impressively for a 7kg unit.  Its not explicit but it reads like a switching power supply but with regulation and ripple to rival the best linear supplies.

After all of the earlier posts, I was looking for a bench power supply - the RF transmitter/receiver project I am on at the moment needs two independent voltages, one of which I need to vary from 1-12V. It was just cheaper than any other dual rail power supply so I went for it. I can't remember how many 5V wall warts I've frazzled now as well (I have maybe 30 in a box, all old phone chargers).

I do have to admit, I'm pretty happy with it - it seems to perform well. It works up to about 32V/3.2A on each channel. Maybe my only complaint is the single output on/off button - though it does make a satisfying series of clicks as all 4 sets of relays come in and out. I may even try it with a powerful audio amp to see how it copes!

[Hypernova]

Am I correct to assume that this Atten APS3005S-3D is just a superficially touched up Mastech HY3005F-3?

They appear to have the same spec too except that the Atten is nearly 5Kg lighter ?

And what does Atten mean by this line in their spec?
Series Parallel Working Method:
-series adjustable rate: ?300mV

Would be odd if it means the combined error in series since it's far larger than the independent errors combined.

In Aus the Atten is $70 cheaper than the Mastech so I'm thinking about it given my low budget. I need something that's good for 5A@24V for sure.

[saturation]

Atten in a peculiar company, they do design their gear rather than rebadge; but they have been linked to making copied designs, one infamous one is the Rigol 1000s series which led to litigation in China.   Some posts suggested they are an ODM for low end scopes by LeCroy.  Their brand build quality tends to be less refined [compared to when they ODM], and choice of specs often leads to user disappointment compared to other brands. 

http://www.electronicskb.com/Uwe/ForumPost.aspx?article=au-electronics:5911:13a6720e-08ce-4ef5-8780-39843642e877%40b9g2000yqm.googlegroups.com

https://www.eevblog.com/forum/index.php?topic=40.msg231#msg231

But a power supply is such a low tech device, it would be easy to repair or enhance what they did wrong, so long as those added cost don't equal your savings by buying another brand.  If you can see the device, try it, and potential return it, I'd look at it.

Otherwise, IMHO, Mastech has a better reputation.

Am I correct to assume that this Atten APS3005S-3D is just a superficially touched up Mastech HY3005F-3?

They appear to have the same spec too except that the Atten is nearly 5Kg lighter ?

And what does Atten mean by this line in their spec?
Series Parallel Working Method:
-series adjustable rate: ?300mV

Would be odd if it means the combined error in series since it's far larger than the independent errors combined.

In Aus the Atten is $70 cheaper than the Mastech so I'm thinking about it given my low budget. I need something that's good for 5A@24V for sure.

[cybergibbons]

As promised, I took the cover off the GW Instek GPS-4303. All in all, impressed, but there are a few strange aspects.

http://www.flickr.com/photos/cybergibbons/sets/72157624310102322/detail/

The performance so far has been pretty good. It can deliver the full rated power for a good length of time, and can also drive a fairly powerful audio amp.

Comparing it to the Caltek on http://www.rcgroups.com/forums/showthread.php?t=1030827 there are a number of similarities and differences:
* Physical construction including heatsink, case, and front panel are very very similar.
* Board layout is approximately the same, though noticeably different.
* Soldering quality appears to be better on the Instek.
* More fuses on the Instek
* Extra output transistors on the Instek (I presume for the extra channels)

Hard to tell if the Caltek is a clone of the Instek, or if they are made by the same factory, and if so, if they are made to different quality standards.

I'm fairly happy anyway.

[saturation]

Does the Caltek also use a toroidal transformer?  These are much better to use for cleaner power, but they cost more than laminated core, so just seeing that in the Instek is a good sign of things to come.   The workmanship is very good, and except for that floating PC board, it does look like a 10/10, as expected from Instek.

I recently bought the 3A Maxtech I'll dissect later for comparison.  I don't expect it to have a toroidal but we shall see.

Soldered fuses is something I increasingly see in Chinese designs.  It isn't bad these days, as in decades of use I have rarely seen a fuse blow without an internal fault that will require more than just a replaced fuse to fix.  In PSU, the overload protection circuits should kick in to make fuses a last resort for safety.

Thanks for the photos, CG.  Very well done.  You also take very good photos, of all kinds of subjects including your friend ... you may have another professional calling if you choose and so could she, she knows how to and has the lines of a model, compared to so many in Flickr.  Now back to electronics !

As promised, I took the cover off the GW Instek GPS-4303. All in all, impressed, but there are a few strange aspects.

http://www.flickr.com/photos/cybergibbons/sets/72157624310102322/detail/

The performance so far has been pretty good. It can deliver the full rated power for a good length of time, and can also drive a fairly powerful audio amp.

Comparing it to the Caltek on http://www.rcgroups.com/forums/showthread.php?t=1030827 there are a number of similarities and differences:
* Physical construction including heatsink, case, and front panel are very very similar.
* Board layout is approximately the same, though noticeably different.
* Soldering quality appears to be better on the Instek.
* More fuses on the Instek
* Extra output transistors on the Instek (I presume for the extra channels)

Hard to tell if the Caltek is a clone of the Instek, or if they are made by the same factory, and if so, if they are made to different quality standards.

I'm fairly happy anyway.