How does a high voltage differential probe work? How is it safe? Is it isolated? A teardown and some reverse engineering of the Lecroy AP031 25MHz HV Differential probe. a.k.a Sapphire Instruments SI-9001 Forum HERE Podcast: Download

Dave takes a look at how to optimise the low burden voltage multimeter design from PART 2 to eliminate some parts. And explains the µCurrent shunt circuit design and how that applies to this new optimised design. It’s basically a practical tutorial in circuit design optimisation. Then another design variation …

Mailbag time again. Forum HERE SPOILERS: Dave’s first multimeter hack! Sinclair PDM35 Multimeter Russian analog multimeter Canyse 801 data logger Kickstarter Masso CNC Controller Lumintop Prince 1000 lumens flashlight torch Lumintop micro USB rechargeable 18650 cell teardown Canon Ion Still Video Camera and the VF-50 2″ floppy disk Podcast: Download

Dave looks at the current measurement front end of a typical multimeter and figures out how to redesign it for lower burden voltage. It’s not quite as easy as you might think, there are comprimises and traps for your players. And something you probably didn’t know about HRC fuses. µCurrent …

Inside the cheap arse Jaycar SL3467 “Rave” DMX controlled RGB LED disco party lights scored for $1 from the dumpster sale. Did Dave get ripped off? Podcast: Download