I have made this kit up and it works - But, while the pause is adjustable within the (approx) 2.5 to 60 seconds range quoted, the pulse (which should be between 0.5 and 5 seconds) is all over the place. If set to fully clockwise it stays on near enough for ever; to adjust it to the 5 seconds pulse i require, it has to be set just off from fully anti-clockwise - but then sometimes when i power it up it pulses for +/- 20 seconds.
Does this mean that the pulse trimpotentiometer is faulty, or have i done something wrong in the assembly process??
I am going to be using this kit to power a 3.8 amp water pump, so i have incorporated a bigger relay into my test circuit.
I am running this test circuit off a car battery that is giving a reading of 15.5 volts.
Could either of the above two issues affect how the pulse is operating?
[NB: The 2 trimpotentiometers in the kit were virtually impossible to distinguish from each other. Only by using a magnifying glass could i make out that one of them had a very faint marking “50K” (therefore i used this as the pulse one). The other had no marking at all…]
Please check operation of the kit first when built and used as indicated in the manual, before modifying it.
You can check the value of the potmeters by measuring the resistance with a multimeter. Measure between the two pins that are closest to eachother. 16V is the absolute max. voltage for the NE555. Sorry, this forum does not allow picture uploads
If you can provide LINKS (e.g. by using a free online picture base) to HI-RES and SHARP pics of your assembly (both solder- and component side) then we can take a look and provide some feedback.
To clarify - i have built the kit as per the instructions. The bigger (extra) relay has been incorporated between the kit and the pump.
I only have a very basic analogue multimeter, so can’t measure resistance. Is this to tell the two potmeters apart, or is it to check that they can take the high voltage from the car battery?/ (Which i have just re-measured - and it is close to 16 volts…)
I don’t use online picture bases. Can i e-mail photos to you…?