Hi Jay_Diddy_B,
I liked your design of the ERS meter so much that I thought I would build one too.
On two radio flea market's, I bought some 50uA meters for this ESR meter.
There is only one component that I have changed in the design, and that is the 5V stabilizer.
I had some low power LDO stabilizer in a TO92 housing and that is the: TSTS2950-50
The dropout voltage when loaded with this ESR meter (24mA) is less than 5.5V.
This allows me to extract as much energy from the 9V battery as possible.
Picture time!
To minimize errors, I mark the parts on a print in the diagram, not all parts are marked, because I did not think this was necessary anymore.
The top of the printed circuit board.
The structure is almost the same as the schematic, I think this is a pleasant way of building electronics.
Top left is the battery connection, the two connection pins at the bottom are for the D.U.T. the diode's ES1J wil come behind the banana jacks.
And the connection pins in the middle are for the meter, the top connection is for the +connection of the meter.
In the blue circle you can see R24, 12K for a 50uA meter, in the yellow circle is the only aberration, the 5V decouplig capacitor C9 under a angle.
The bottum of the circuitboard, no spaghetti wiring
The top wire is the +5V power supply, the wire below that is the connection from Q3 that drives Q5.
And on the bottom is the -rail.
And yes, he worked on the first power on.
The meter indicates 35uA when measuring a 1 ohm resistor.
Now it is time to look for a instrument box, I'll show it here when the project is done.
Nice project!
Kind regards,
Bram