Control Condenser Charge and Discharge

Thread Starter

Justino

Joined May 21, 2014
2
Hi Everyone,

I'm into this exercise where i have to accumulate charges on a condenser and discharge all the accumulated charges when it reaches a certain level.

I have the following circuit, composed of sub-circuits A and B. I use a manual switch to open and close these sub-circuits.


- +
---------|voltage source|----------
| |
| sub-circuit A |
| |
| - + |
|---------|condenser|---------/ <----- switch
| |
| sub-circuit B |
| |
|-------------(LED)---------------|


When sub-circuit A is closed the condenser is charging. When the condenser is charged i use the switch to open sub-circuit A and close sub-circuit B, thus lighting up the LED.

I'm very lazy, so i'm looking for something that controls the switch automatically:
1) when the condenser is charged the switch must open sub-circuit A and close sub-circuit B automatically to light the LED.
2) when the condenser is "empty" the switch must close sub-circuit A and open sub-circuit B automatically to charge the condenser.

Is there any eletronic component that can read the charge on the condenser and open and close a switch automatically?

Than you
 

Bernard

Joined Aug 7, 2008
5,784
If you are happy with C charging to only 2/3 of V & discharging to 1/3 V, then go with pwdixon, or else list your requirements or make a simplified 555.
 

Thread Starter

Justino

Joined May 21, 2014
2
Hi guys, thanks for the replies. I've done a sketch so it's easier to understand what i need..



So i need some kind of voltage controlled switch that allows me to discharge the capacitor when it reaches a certain voltage level.
I've read about the 555 which uses voltage comparators and flipflops. Is this the simplest solution? Any hints about how could this be implemented?

Thank you
 

Bernard

Joined Aug 7, 2008
5,784
Is there a purpose to this experiment?
With 5 V battery, 555 trip points will be about 1.6 V & 3.3 V, so you will need to make your own @ 1 V & 4 V. You will need some resistance in series with LED, say 120Ω, & a resistor in parallel with LED to drop V down to 1 V. With 1000 μF LED will flash for about 1/10 sec.
, recharge maybe 1 ms
 
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