rusefi.com

I soldered together this MAX9926 circuit.
https://www.pcbway.com/project/shareproject/Dual_VR_Conditioner_Regulator_b4846e9a.html

Then I added a sine wave to it using the signal generator. From a signal voltage of around 70mVpp, the output produces a square wave signal. If I now increase the frequency, the output stops working at 90 Hz. If I increase the voltage to 1Vpp it goes up to 120Hz and then the signal is gone again.

It is clear to me that the signal voltage increases as the speed increases. But in what range is that from start to maximum RPM.

I would be interested to know what signal voltage such a VR sensor actually outputs.

Thanks to the resistors built into the board and the internal diodes, nothing should break even if I increase the voltage further, right?

I'm now up to 20Vpp, but I can't get more than 2500 Hz. Does anyone have an idea what it could be?

Here 2 pictures once at 300 Hz and once at 2500 Hz I go to 2600 Hz the output is permanently high.

What signal are you using to stimulate it? Exactly how is it connected?

i use a signalgenerator Rigol DS1022Z with a pure sinus without the loosing toot.h

C1, C4 should be 1nF according to DS, while I see 1uF on schematic.
Check signal on MAX inputs

o.k. thanks i will check if a have 1nF to change it.

To test it it would have to work without the capacitor? I can then definitely set the sine voltage lower.

Thomas18TE wrote: ↑

Sat Jan 13, 2024 11:54 am

To test it it would have to work without the capacitor? I can then definitely set the sine voltage lower.

It should work without capacitor. But will be affected by noises. On real car at least. On table should work fine with no cap.

So thank you very much, I removed the capacitors and now there are no more problems. 12kHz works great even with a level of only 5Vpp.