Hello. I have a bug zapper (manual fly swatter) that looks like a tennis racket.
I know that it's estimated around 40 microcolomb and it's not harmful but I plan to change the capacitor to achieve insane spark
I wish to modify the circuit in a manner that when human is touching the grid so the circuit will detect the typical 500ohm resistance of his body and cut off the capacitor therefore prevent it from discharge on human.
This upgrade can be useful to protect kids and pets. I am really interested to get from someone here idea of a circuit and learn and investigate it.
I may remark that the sensor/filter has to be protected from the capacitor itself which is 40uF 2kVDC... Maybe with a diode or transistor?
If you were to design this circuit... How would it look like? Can you upload a scheme?
Thanks.

 

Welcome to AAC!

If you were to design this circuit..

I wouldn't. It's potentially LETHAL!

 

Welcome to AAC!

I wouldn't. It's potentially LETHAL!

My goodness!!
Can you provide me mathematical evidence for the danger?
I am sure that the current is minor...

And why wouldn't you? The porpose of the circuit is to protect against injury...
I can implement it even without replacing the capacitor to bigger one.

Thanks.

 

This thread was locked for safety reason..

 

My goodness!!
Can you provide me mathematical evidence for the danger?
I am sure that the current is minor...

And why wouldn't you? The porpose of the circuit is to protect against injury...
I can implement it even without replacing the capacitor to bigger one.

Thanks.

A 40 uF cap charged to 2 kV is storing about 80 J of energy. The 2 kV is more than sufficient to punch through the skin resistance. An AED typically delivers about 200 J at 3 kV in less than 1 ms, so this circuit is getting into that territory. Given the extreme variability of contact resistance that a human is going to exhibit, your zapper has a very high chance of discharging into them before any protection circuit could respond.