Superscan PI

[Carl-NC]

Generic PI Debugging:

1. Make sure all the power supplies have proper voltage. Especially if you have a charge pump.

2. Check all pulse timings to make sure they are correct. Not just edges, but also levels.

3. Measure the TX waveform (be careful not to overdrive the probe or scope); verify turn-on and flyback.

4. Measure output of preamp; verify correct waveform.

5. Check demod output(s); they should be steady and approximately mid-voltage without a target. Wave a target and they should respond.

6. From there it depends on the design, but mostly check the following SAT, gain, threshold, and audio stages.

[ZOUjiarui]

Generic PI Debugging:

1. Make sure all the power supplies have proper voltage. Especially if you have a charge pump.

2. Check all pulse timings to make sure they are correct. Not just edges, but also levels.

3. Measure the TX waveform (be careful not to overdrive the probe or scope); verify turn-on and flyback.

4. Measure output of preamp; verify correct waveform.

5. Check demod output(s); they should be steady and approximately mid-voltage without a target. Wave a target and they should respond.

6. From there it depends on the design, but mostly check the following SAT, gain, threshold, and audio stages.

Hello, a master told me as long as the adjustment 709 next to the 100K resistor, you can give me more explanation, thank you!

[Qiaozhi]

Hello, a master told me as long as the adjustment 709 next to the 100K resistor, you can give me more explanation, thank you!

There's no point trying to fix the problem using guesswork. You should have built the detector in stages, and tested each stage before moving on to the next one. The only solution for you now to is follow a logical fault finding approach as outlined by Carl.

If you really don't understand correct fault finding procedures, then you should seek first-hand help from a friend who does, as it will be enormously difficult for anyone here to assist you remotely.

[eclipse]

What circuit do you use? If you just solder parts on the board and call for help is not a good idea. No one would be able to help you with this.
Provide more information about the circuit you're using /schematic not PCB/.
After that verify +5V and -5V as starters. Measure the TX signal on mosfet gate /no coil connected/.
Next steps would be preamp out, integrator out /then SAT which is a bit more specific stage to Eric Foster's designs/ but lets see first things first.

[ZOUjiarui]

I'll measure it carefully until I find a mistake.

[ZOUjiarui]

The machine has a pit, I found the problem, I want to rebuild it.

[ZOUjiarui]

The machine has a pit, I found the problem, I want to rebuild it.

pcb

[bernte_one]

[ATTACH]55289[/ATTACH]

can you upload the layout files please?

[ZOUjiarui]

can you upload the layout files please?

I Don't understand English, and it is difficult to upload with translation. Its layout is the same as that circulated on the network, and there are almost no problems with the circuit layout.

[ZOUjiarui]

[bernte_one]

I Don't understand English, and it is difficult to upload with translation. Its layout is the same as that circulated on the network, and there are almost no problems with the circuit layout.

you can upload the layout into an cloud server and then put the link for download here, or you can send it to me via email please

[TufaN]

you can upload the layout into an cloud server and then put the link for download here, or you can send it to me via email please

You can download from here

[Op04]

Damping value is so low opposite with delta, what happen if using 1k for damping? Will it cause oscillation or kick back voltage going to destroy the MOSFET? Anyone have experience on this?

[kt315]

with big relatively FIRST SAMPLE DELAY you can use 1k. just it was in DP sch. meant 40...50us.
but if you want to get minimally FIRST SAMPLE DELAY you must tune the damping decreasing value.
in first case your sample lies in a zone OFF/OUT self resonanse.
destroy MOSFET? MOSFET is in TURN OFF state. it will cut voltage if it is more than maximal, like a zener diode.
for IFR740 it is 400V. so you can not get more than 400V of delta pulse.

[Op04]

Mine first sample delay is 45us. Thank you master KT315. I will try using 1k damping first, I use IRFP460 a bit warm but still negligible