Electronic – Simple way to create a disturbance on DC power

First of all, i must say that I am a software engineer, with very-low to no experience in circuits designs, and a very rudimentary understanding of electrical engineering and circuits. 101 really.

For a software project I am playing with I have built a small physical gauge simulator using some ready-made cheap 7-LED and old needle voltage and amp gauges.
They are all powered from a standard DC 24v 3A power supply and I am using a potentiiometer to make the values change manually when i need to change them.

My challenge is the following :
Is there a simple way, without special components / devices (NOR MCU arduino/pi to make the gauges "jump" automatically and basically mimic the operation of me fiddling with thee potentiate ? Basically some kind of a DC oscillator – but random jumps are ok.

I do not have an the option (time-wise) to buy special components but I do have a lot of standard ones, ranging from capacitors, to resistors, DC power converters, diodes, LED's, Fuses, transistors (PNP,NPN, mosfet), coils, magnets photoresistors, humidity sensors etc.
On the device level I have some low-voltage motors, steppers and solenoids.
There is a bit of everything in the very-basic range of stuff.

Is there a simple circuit that can help me achieve this "jump" in the power without any code ? ( funny question for a coder – I know. but there IS a logic behind the project :- )

EDIT I :
Here is a picture for better understanding .

EDIT II :

I ended up using a combination of 2 solutions :

A – I took a solenoid that was producing heat and connected it to a relay via and NTC ( PTC would work the same I assume ). The NTC got heaat from the solenoid and functioned like a "gate" for the relay, which also started a small fan to cool the solenoid again. The solenoid operation also made the amp jumps .

B – I Friend brought me an ne555 which I connected to relay. ( but that's an oscillator – which was a few days later )

Although these primitive methods work, I would still like to hear other advice on how to achieve that in some other way .