Try uni-com. I have a three socket hand held remote that has not failed in over a year.

They can be obtained local and Amazon.

A car battery will do the job to test.

Try a battery on the motor first to see if it is up to the job.

The relay is available from places like Amazon in 8 lead. Just cut off the leads you don't want, close to the relay cover, and cover them with one of two layers of insulating tape. As for the capacitor I have to guess, that it is a 630 volt suppressor for the contacts on the relay to stop arcing.

I am thinking like David. I would fit an isolating valve in the toilet feed [ perhaps one is already fitted ] to adjust the rate of fill. To guess what is happening to the shower.... The toilet is taking all the water on refill, and putting the shower below its minimum range of water pressure, thus ...

I have to stick to my original proposal. I have done the maths, simulated it, and find it is fine. What I have to make clear is that is when I proposed to make up the power pack, I should have said the cells would be dry, say AA batteries times 2 given 3 volts to start. This could then be increased ...

I would stick with the idea of having them in series, that way when one lights up it shows the circuit is complete, and working.You can make up your own battery pack using say 2 cells to start, seeing if the LEDs are bright enough,if not then increase the number of cells to 3.If you have to you can ...

I would go for an Arduino Uno...I think they are up to rev 3, but I am quite sure, any one of the range will do for what you want. As this is open source, there are many companies out there that have developed their own Arduino, and may give the same results. However, you are encouraged to purchase ...

There may be many ways to come up with a solution to your problem, but I have only been able to come up with what I would consider. That is...a 555 astable, to give a one second sample, a digital to analogue [DAC],and a window detector.However it would appear to me that you would be better off, fina...

Try a buck converter.This device can be purchased in a modular form and ready to go, with just 2 wires in, and 2 wires out.The output voltage is adjusted by a multiturn
potentiometer on the unit. Amazon e boot 6 pack LM2596 about £9.