'fraid that a little bit of effort producing the circuit diagram from the boards is really needed.
I think that it will show what has to be a microcontroller with an input pad going to the switch and another pad going to a base resistor for q1. Q1 switching power to LEDS via RA - D.
The long light looks to be fitted for a an IR receiver. With U1 near it possibly the decoder. As they show the thing stuck on a rafter presumably way out of reach - I suspect that 's a picture from the version with an IR controller. They have produced a cheaper version, without the sensor and re-used the photos.
Now, if that’s how it is - I’d just remove the microcontroller and glue one of my favs upside down on the board and run wires from its pins to the relevant pads (removing the existing microcontroller). I haven’t bought one recently, but 8 pin ones were costing me less than 50p… Having programmed the replacement with an added option to stay on.
For the first one: Would be good to know what U1 is exactly. Can you read any number/code on it?
If you are lucky it is simply a ‘switch’ which switches on once you press the button and switches of after 30min. In this case you could add a wire which constantly switches the lights on. Then add a normal mechanical switch to the power supply cables.
If you are unlucky, U1 also regulates the current through the LEDs. Then cannot be easily replaced. Is there anything on the other side?
First image: U1 says HZ300 0053, and Q1 says 3400A. The second image has two U1 components: the smaller says RCAKL9 00765, the larger is 6228A 2121/33, and the Q1 is 3400X. There’s nothing on the back of the board.
Can you read what u1 and q1 are in the first image? Q1 looks like a transistor switch and u1 might be a counter. It may be counting a clock or it might be a comparator checking whether a capacitor is charged or discharged to check time. Is there any components on the other side of the board? I would expect a capacitor or oscillator at least for timing.
First image: U1 says HZ300 0053, and Q1 says 3400A. There’s nothing on the back of the board. The second image has two U1 components: the smaller says RCAKL9 00765, the larger is 6228A 2121/33, and the Q1 is 3400X.
Since writing this though I realised something important I had forgotten - these are rechargeable cells. And if they are wired in series, it means I need a much more complicated charging circuit (I currently use TP4056 boards to charge cells).
So even though series might be more efficient, I think I'll need to use parallel as a single TP4056 can charge two cells in parallel.
Funnily enough I have exactly the same set up on my healing bench right now, and was wondering about the same thing. Thanks for posting the question and your realization.
It's probably just the converter... something misconfigured in the drivers or... who knows. Try and see if you get the same garbled data in Windows and Linux (binary check). If they match, it's something hardware wise.
Back in the day, yes, the Chinese USB to Serial/Prallel converters were terrible, no doubt there. But, over the years, they've gotten surprisingly good. In fact, I picked one up a few weeks ago (as you said, about $5), works like charm.
Type C 2.0 exists and is widespread and that is what I wanted, the issue is that it doesn't work as a 2.0 cable either. I like the liquid silicone exterior and I have a few connectors ready so if I like what's inside I may upgrade it. Otherwise I will recycle it and I already have better cables.
You can make your own current-limited power supply, probably from bits and pieces you already have. Let's say that you have a 5v dc power supply and a hand full of rectifier diodes and resistors (various values and sizes).
Put a series chain of forward biased rectifier diodes and resistor(s) across your 6v supply. Choose enough diodes to give you a 3v output. Now choose a combination of series/parallel resistors to give you a 2v drop with a current of, say 100mA. You need 20 ohms - so that could be 5 x 100 ohm resistors in parallel.
The most current that can put out is the full 5v across 20 ohms - but at that point the output voltage will be near zero.
Bench supplies, well reasonable ones, allow you to set a current limit as well as an output voltage. At loads below that current limit - it operates as a constant voltage supply. At loads above - it operates as a "constant current" supply. You would set the output current limit to 100mA and that's the most that it will output.
Now the rectifier diodes plus resistor would allow the current to increase above 100mA, up to 250mA when the output voltage will be near zero (short circuited) - if you want better than that, then you can add a transistor and a few other components.
Interesting, I've never thought of doing it exactly this way. Usually I see high surface area PIN junctions used to detect particle impact either by reverse biasing the junction or by directly measuring induced voltage. The amplification stage is not so easy. This is for particle counting and energy measurement though.
What kind of radiation are you measuring? Gamma I guess?
I guess the first thing that comes to mind is that for a given signal, as Vgs increases perhaps the on-resistance at a given voltage does too? If so, it might be easy to measure the voltage drop across the MOSFET on resistance and how it changes with dose.
If I think of anything else though, I'll let you know!
Edit: I suppose you could also use an R/2R network to provide an increasing voltage to the MOSFET base, and measure the point where the output reaches some threshold, a direct measurement of Vgs. That should be pretty easy using one full output port of an Arduino and one of the ADCs.
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