Hello, New to the Arduino Uno. I would like to build a capacitor bank charger using the Arduino to control charging and discharging. The bank would reach around 400 volts dc. Is there a way to monitor the voltage using the Arduino to shut the supply off at a certain voltage? Voltage Divider?
It would be a voltage divider, but - what is it that you would want the Arduino to actually do?
I would like the Arduino to shut off the supply to the bank when the bank reaches a certain voltage. (350 volts)
Voltage divider, carefully designed to be failsafe - a capacitor bank at 400V has to be
treated with utmost respect. In particular the upper resistor in the divider needs to be made of several high-voltage rated resistors in series so that the failure of any one resistor cannot cause high voltage to appear at the output, which needs voltage limiting device such as power zener or TVS.
How do you plan to have the Arduino control the power source?
I would suggest limiting the contact between the Arduino and your capacitor bank. I have already made a capacitor bank like this, but to charge it, I used the circuit of a disposable camera, I got it for free at a camera store, just ask for some used ones that people throw away after use.
Then, hack the "flash is ready light" from your camera circuit board into your Arduino circuit, so you know when your cap bank is full. (light turns on, i.e, small signal appears on this line).
Just be very careful when testing, not to electrocute yourself, always short your capacitor bank before working on it (I use a screwdriver with a big rubber handle)
I have also successfully added on 30 capacitors to this circuit, to make the bank much larger. I just takes longer to charge.
The charge is controlled by switching the flash on/off switch from the circuit board, which can easily be hacked on the Arduino with a transistor.
The charger is a 12 volt step down transformer in wich the secondary is connected to a 555 astable circuit that pulses a 12 volt square wave through it via a couple of mosfets (INVERTER). The primary is then connected to a voltage tripler. My plan was to have the arduino monitor the voltage then shut off the charger.
TACAMO:
The charger is a 12 volt step down transformer in wich the secondary is connected to a 555 astable circuit that pulses a 12 volt square wave through it via a couple of mosfets (INVERTER). The primary is then connected to a voltage tripler. My plan was to have the arduino monitor the voltage then shut off the charger.
That's a reasonable approach, although you don't really need an Arduino for this, you could use a comparator connected to the 555. Or you could use the Arduino to generate the square wave mosfet drive signals directly. I suggest you also have the Arduino cut off the charger if it doesn't see the voltage rising after the inverter has been on for a short while.
Did not think about using the Arduino in place of the 555. How would I go about connecting a comparator to the 555?
Thinking about it, connecting the comparator to the 555 is not what you need, because you need to turn both mosfets off when you stop the inverter. How were you going to do it using the Arduino? Perhaps with some gating between the 555 output and the mosfet gates? If so, then the comparator could drive those gates instead of the Arduino.