Drain pump controller - need some help understanding

Hi,

I am trying to find a solution to an old problem I have at home. I have drainage water from the basement going into a cesspit, which contains an immersion pump controlled with a float switch. Sludge collects around the float switch, until it gets stuck, so regular maintenance is required. I was trying to find a better way to do this and eliminate the float switch completely, and found this: Homemade Nixie Clock 2x3 Mux

By the look of it, that's exactly what I need. I don't really need the counting LEDs however, but I can easily remove that part off the circuit. However, there are some missing details in the diagram, and since I'm not really an electronics expert, I don't know how to correct them. So here are my questions:

1. On the diagram there are 4 symbols that look like NAND gates. Am I correct to assume that they are all parts of the same 4011 IC?
2. There are also a number of capacitors with no spec. From what I can get from the photo, is that they are some blue ceramic capacitors. There's also what appears to be one big capacitor. Any idea on what I can use?
3. Before the relay, there's an NPN transistor with no spec. Will any NPN transistor do?
4. There are also 3 resistors without spec. What resistance should I use?
5. Same goes for a number of diodes. Will any diode do?
6. On the top right of the photo, just above the big capacitor, there's what seems to be some 3-terminal component. Any idea what that is?

Sorry for all the questions. I would be very grateful if you can help me out. Thanks!

Hi,

1. Yes, all NAND gates from the same IC.
2. Not important. Use 10n - 100n. The big one is the supply cap and he says it's 2200uF and fed from a bridge rectifier from a 9VAC supply. If you have a 9VDC wallwart/plugpack handy you don't need the 2200uF (use a 10uF or 100uF - or pretty much whatever you have available - instead) or the bridge rectifier.
3. It has to be rated to get enough current to drive the relay, so it depends on you relay choice. BC337 or 2N2222 should be fine for most 12V relays. Also be sure your relay can handle the pump current.
4. All resistors inline with LEDs can be 1k. The one on the base of the transistor could be 10k.
5. Yes. 1N4148 or 1N914 would work fine too.
6. That's a bridge rectifier and it's got 4 terminals

Hope that helps. If you're interested - which you probably won't be - you can do all that (w/o the counting LEDs) with a single hex schmitt trigger IC (e.g. 40106 / 74C14).

Thanks a lot for your help! I would rather not change to another IC as that would mean changing everything probably.. and I'd better not risk that

One final question. To the right of the 4013, there's a resistor which then goes to ground. Is that a 1k resistor as well?

hi,

4013 can be removed, see the attached.

razeen

BigRiz said:

Thanks a lot for your help! I would rather not change to another IC as that would mean changing everything probably.. and I'd better not risk that

Click to expand...

As you wish. If you've started building it, then yes, you'd have to change a fair bit.

BigRiz said:

One final question. To the right of the 4013, there's a resistor which then goes to ground. Is that a 1k resistor as well?

Click to expand...

10k should be fine. Actually, all the resistors marked 1k or 1k5 for the LEDs should be increased a little to maybe 2k2 to reduce the load on the IC.