Good day

I was wondering if it I could get some advice with a project I'm working on.
I wish to wire a window comparator circuit so that it will help me control when a capacitor bank will discharge voltage as an output
What would be the best way to do this? Do I even need a window comparator circuit or will I be better of with a 555 timer?
Note: I will be dealing with highvoltage obtained from a boost converter.
I'm really new to electronics so please forgive my ignorance

 

What you would be better of with depends on the details of what you are trying to do. It might help if you let us in on what you mean by "control when a capacitor bank will discharge voltage". What determines the "when"? When there's a full moon?

 

Oh sorry, I want it to discharge the capacitors when they reach a threshold like 50 volts.

 

Oh sorry, I want it to discharge the capacitors when they reach a threshold like 50 volts.

So what were your thoughts that were leading you to considering a window comparator?

So what were your thoughts that were leading you to considering a 555 timer circuit?

For THIS application, what does "discharge the capacitors" entail?

What is causing them to charge?

How are you going to discharge them?

How will you know when to stop discharging them?

Questions like this are important because it isn't a simple matter of a generic circuit that is going to tell you when to discharge them. The fact that you are considering two very different approaches indicates that there is more to it than that.

 

Oh I see I see, since I was going to charge up the capacitors using the boost converter and use the window comparator to detect if the capacitors were charged and then use perhaps an IC to turn off the boost converter so the discharge may be routed to two wires connected to pins on a usb. The reason why I thought if I should use a 555 timer instead was the idea that maybe it would be easier to simply have the boost converter turn off at timed intervals so the discharge can occur as routed with out having to detect the voltage. But I don't think the 555 timer could handle the high voltage.

Even after some reading, I'm still quite confused on how the capacitor works, but by discharge I mean that it will send the stored voltage (assumingly higher than the voltage into the boost converter) into something else before having to be charged up again by the boost converter which I want to turn on again after each discharge

 

I'm definitely not following something. You are concerned about high voltages being around a 555 timer circuit, but yet you are going to route them to pins on a USB (as in Universal Serial Bus?).

The high voltage concerns can likely be taken care of with voltage dividers (and perhaps optocouplers) or something similar, depending on details.

How does the boost converter behave when it is turned off? Does it act like an open circuit, or do the capacitors drive it in some manner?

Again, what does it mean to discharge this capacitor bank? Are you solely trying to dump all of the charge out of it? Are you trying to use it to power something until it falls to some lower threshold? How are you planning to discharge it? How long will it take to discharge it?

 

Ah Yes! I intend to solely dump all of the charge out of the capacitors as fast as they allow, so I won't try to lessen the rate at which they will discharge. As for the boost converter I wish for it to act as an open circuit until such time that it is turned on to charge the capacitors again.
What I aim to achieve in this circuit is to take a small charge, amplify it, and then shoot a negative charge similar to a short and then repeat the process.

 

Hi,

It sounds like you want to detect the higher voltage set point so you can start the discharge, then detect the lower voltage set point so you can stop the discharge.

If that is true, a comparator circuit is often used for this purpose. It provides a low voltage output that is at a high state when the voltage is high, and a low stage when the voltage is low, thus telling the drive circuit when to discharge and when to allow it to charge. So it would be a window comparator with lots of hysteresis. These are relatively simple circuits.

The output drive and input conditioning however depend on what it is you have to drive, what kind of signal it requires, and also what kind of inputs it will be looking at.

So a question for you is, what is the high voltage and what is the low voltage set point?
For example, if the low set point was 50v and the high was 100v, then it would allow charge up to 100v and then force discharge. When the voltage got down to 50v then it would again allow charging.
An example of the output would be that it turns the converter on or off depending on what the output of the comparator was at the time.

Again, this is a relatively simple circuit but you have to specify at least three things:
1. Low set point voltage in volts.
2 High set point voltage in volts.
3. What is being turned 'on' and 'off', what kind of signal that needs, or what it is exactly that is being turned on and off.

A timer circuit isnt that good of an idea because the timing of another timing circuit is not that repeatable because values change over time.