High voltage polarity inverter circuit

Question

I'm building a cloud chamber which needs to use an high voltage source. I'm using an electric fly swatter circuit which can generate about 4kV. The fact is that I want to use a button to switch the polarity of the output of this circuit. In the cloud chamber there are two metal peices to which I've connected the output terminals of the HV circuit, this creates an electric field, so that electrons are repelled or attracted to the metal plate which is placed inside the active region of the chamber (that is the region in which particle can be seen) . I've tried to search online for some circuits that can invert singnals polarity: some designs which I like use a 555 timer like this one:

The fact is that 4kV is a very high voltage to handle, and I have no idea on how to adapt it to the mentioned circuit.

I include a schematic of the fly swatter circuit, which, I think, Is something like this (I've already modified It a bit by shorting the push button with a tri-state button, so that the generator can stay on for long periods of time:

So, is there a way to add a polarity inverter circuit on the output of the electric fly swatter circuit? Or, if not, how could I modify the fly swatter circuit itself to add this feature?

Thank you in advance for your answers, and excuse my english: I'm still practising it!

Answer 1

Simplest: use relays. See: Change Direction of 12v DC Motor Rotation using Relay

For high voltages, you will need specialty relays, which will be expensive. But it is the most straightforward solution.

Purely electronic methods are significantly more complex: either the equivalent circuit with transistors (many in series to handle the high voltage, preferably with protective circuitry to handle the inevitable spark discharge), or use two power supplies, wired such that one or the other can be powered to set the output polarity.

An equivalent solution might be building a relay by hand, using bits of wire, foil, plastic, etc. Your application needs very little current handling, as I understand it. But the design of such is beyond the scope of this question.