Negative pulse generator

[fmnotes]

Hello
knows someone, a circuit for a negative pulse generator?
eg with a 555! ????????
Thank you.

[ANDREAS]

Calculate R1,R2,C1 for duty cycle and out Frequency
You can use power supply <18V. Diodes are not critical
regards

[ANDREAS]

opps sorry for a small false. Remove output elec capacitot 10 uF
Regards

[reza vir]

Hi Andreas
The device can be tested pd & pdk & static & .... ?

[ANDREAS]

Originally Posted by reza vir

Hi Andreas
The device can be tested pd & pdk & static & .... ?

No reza

[reza vir]

Hi dear friend Andreas
This circuit can detect metal ions?
Thanks and regards

[fmnotes]

Originally Posted by ANDREAS

opps sorry for a small false. Remove output elec capacitot 10 uF
Regards

Thank you my friend Andrea,
I have tried this circuit but I did not found
I have no negative output pulse.
Also I tried to add the little circuit output, and another signal generator but I did and there some negative pulse output.

[ANDREAS]

Remove diode connection ground.
Few years ago, i build it, but i don't remember a small modification. My sense is diode.
I search tomorrow my library, maybe i find it or a better and simple schematic
best regards