temol

Prototype.

One more thing. It may be tempting to make the circuit in SMD, but you have to remember that R4 is a workhorse here, it can get warm. I...

It is worth remembering that the relay contacts in the schematic are in the ON position.

I'm testing this circuit on a breadboard now. With 9V supply and NA5W-K it draws around 3mA when Off and 30mA On (including 3mA for the...

This is why there should always be a resistor in series with the trimmer. e.g. 470R or 1k.

That was the intention :)

My version of the boost. Q1 - MMBF5457, Q2 - MP38A. Enclosure waiting for painting.

Here's simplest breadboard setup for Vp measurement. You can add a switch to disconnect the battery. Mind the pinout!

I've checked my layout ten times before postign it here.. Do you have a breadboard? Same circuit, different layout.

It looks like wiring errors and a transistor not plugged in properly. Here's the pinout for 2N5457. And here's correct wiring.

Your DMM is fine for BJT transistors, not JFETs. You can still use it but not the hFE measurement mode...

Three possible reasons come to mind why you can't set the drain voltage lower. 1. Trimmer value different than it should be (for example...

Check this one also. It's a LED current limiting resistor. 4k7 according to the build doc, but looks like you have silver stripe there.

Check the value of R10 - should be 3k3 (orange, orange, black, brown, brown). Looks like you have installed 3R3 instead of 3k3.

47uF - this is an electrolytic capacitor (polaryzed). Capacitors are labeled with pF, nF, uF. Install DIY Layout Creator and look...