# Constant Current Source

#### ben sorenson

Joined Feb 28, 2022
165
A while back I created this thing, I'm not sure even what to call it. Its a 2 terminal device It's pretty much in-between a battery, capacitor and varistor.

There is a pos _ neg potential that usually floats at around 500mv - 800mv. Also there is an internal resistance of about 25- 50MO.

If I connect the pos _ neg terminals together through a 30 OHM resist and galvometer in series the voltage drops to around 300mv but there is a current of 400uA discharging and a full scale deflection.

I have tried shorting them out and or discharging them for weeks at a time an however the current never seems to drop below 300uA and the galvometer stays fully deflected.

If I interupt the circuit the voltage potential will slowly increase back to that 500mv-800mv range.

I can like a battery connect 2 in series for a higher voltage or in parallel for a higher current.

Is there anyway I can or a better way I can try to discharge them fully so they do not recover?

#### LowQCab

Joined Nov 6, 2012
3,581
Please provide a Schematic Diagram and the
complete specifications of any non-standard Components used.
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#### Papabravo

Joined Feb 24, 2006
20,603
A while back I created this thing, I'm not sure even what to call it. Its a 2 terminal device It's pretty much in-between a battery, capacitor and varistor.

There is a pos _ neg potential that usually floats at around 500mv - 800mv. Also there is an internal resistance of about 25- 50MO.

If I connect the pos _ neg terminals together through a 30 OHM resist and galvometer in series the voltage drops to around 300mv but there is a current of 400uA discharging and a full scale deflection.

I have tried shorting them out and or discharging them for weeks at a time an however the current never seems to drop below 300uA and the galvometer stays fully deflected.

If I interupt the circuit the voltage potential will slowly increase back to that 500mv-800mv range.

I can like a battery connect 2 in series for a higher voltage or in parallel for a higher current.

Is there anyway I can or a better way I can try to discharge them fully so they do not recover?
Sounds about as useful as a screen door on a submarine.

#### BobTPH

Joined Jun 5, 2013
8,104
By my calculation, it takes 7500V to force 300uA through a 25MΩ internal resistance.

Edited to add: And internal power dissipation is 2.25W.

Edited again: Compared to 144μW of output power.

Last edited:

#### ben sorenson

Joined Feb 28, 2022
165
By my calculation, it takes 7500V to force 300uA through a 25MΩ internal resistance.

Edited to add: And internal power dissipation is 2.25W.

Edited again: Compared to 144μW of output power.
It regulates its resistance.