Electronics Circuit Request: 1 Button Fan switch 12v:7v:Off...

Can someone be so kind to show me a circuit diagram for the following:

Using 1 Button(Non-locking, puch to make) to control a fan to jump between 3 states. Push once to 12v, push again to 7v, push again to OFF. I would like both the ON states each to have a LED attached.

Is this easy for someone who can just about manage to mod his Power and HD leds to Bl00?

I know this can be done, probably much more easily, using a 3 state toggle switch, but I want to create my own buttons and illuminate them.

 

I wrote a guide on stuff like this a while back, find it here :

http://forums.bit-tech.net/showthread.php?s=&threadid=24343

 

Hey thanks!

A few n00b questions:

- Would I need to replicate that circuit for each button and fan set? (I reckon I will need about 4 - 5)
- Where can I get a list of symbols dictionary? ( don't know what most of those sybols are)
- Can the output for the fans power 2 fans? (This will be for the Rad)
- For someone who has only really soldered resistors to bl00 leds, is this a hard curcuit to make?

 

I'm assuming your using this circuit:

Question 1 - If you want independent control over each fan, then yes. If not you can hook up as many fans as you like to the fan output (within reason).

Question 2 - You need to check out another one of my guides: http://forums.bit-tech.net/showthread.php?s=&threadid=27158

Question 3 - (see Question 1)

Question 4 - Yes, very. But thats how you learn, i recommend you spend a little time figuring out why I've used each component to understand how it works (see link in Question 2 for help), if you need any more help ask me. You'll need to buy a breadboard (or protobloc) to wire up the circuit before you transfer it to something more permanent (such as stripboard) if you want to get a good understanding of how it works.

 

OK. Wow, thanks for pointing me to your tutorial.

I now know I need 3 opto-isolators, 3 SPDT relays, 3 transistors, numerous diods, LEDs (Bl00), capacitor, an IC4017.

More questions...

- erm...what's the triangle thing near the 4071?
- for the relays, will SPDT 1A Sub-Miniature Relay (Maplin Code UG42V) do? Are there any cheaper ones? That's £3 just for the relays! ...for one fan!

This circuit's starting to look expensive.

 

The triangle thing (401060B) is a Schmitt Inveter (sometimes called a schmitt trigger) it works with the button, resistor and capacitor to 'de-bounce' the switch (because when you pres the button the contacts may bounce several times causing several signals to the chip, if this isn't corected the circuit will apear to select the state at random).

As for relays you can use any with a 6V rating, the price for the one you mentioned seems about average, if have you look around you should find some cheaper ones (about 0.49p).

 

Would it be to simple to get an A/B switch, with a center off, connect the ground to A, 5v to B, 12v to the + on the fan, and the - on the fan to the common on the switch? Just keeping it simple.

 

Yes much more simple, but...

 

I've already got a bay bus from Baybus.co.uk (sorry to hear about those guys) which uses 3 state toggle switch. While they are a much simpler method to achieve what I want, I thought it wouldn't look as nice as a push button that would do the same thing.

What I plan to do is to create some simple acrylic rectangles to serve as buttons. Sit these in front of a PTM buttons. The acrylic will be lit from the back by two leds. I'm thinking Bl00 for 7v and Red for 12v.

Now that I've been given the circuit thats need by acrimonious I plan to try to put this circuit together and experiment, maybe this weekend or the next. Will post images and short animated Gif when I get the thing wokring.

Fingers crossed.

 

I know nothing about electronics. Can someone tell me if my understanding of this circuit is right.

The 4017b is basically a counter. Everytime I press the PTM switch it will give a high signal out of the next successive output.
The relays are none-locking. So it will only close the circuit when and only when there is power going to the relay.

If my understanding is right, how can you get 12v when the counter is at output 1? (Like I said, I know nothing about electronics, knowing only what I've read in acrimonious's tutorial.)

I can see how you get the 7v as when the counter output is at 0, the 5v and 12v complete the circuit and result in 7v.

Should the line under Q1 go to the 12v line instead?


Oh someone pls help me understand!

 

All the Opto's (Q's) do is allow the currrent to bes boosted enough from the IC to power the relay. The relay effectively flicks a switch for you, if you look at the relays you'll see how it works.

Look at RL1 (2nd in) and imagine the switch of it flicked to the other side and follow the power round. Its connected directly to 12v

 

So here's my understanding of how the 3 switches work. I still don't think I fully understand how it works. Anyway, here goes.

From the Counter state 0, RL2 is switched.


From the Counter state 1, RL1 is switched.


From the Counter state 2, RL0 is switched.


I'm most likely to be wrong, but that how I think it works. From the above I can see the Off state and the 7v state. I can't see how the 12v state comes in.

 

Sorry you are correct, that diagram must be an old version or something i've actually built from that scematic.

The input for RL1's output should be connected to the 12 v line, well spotted.

I'll link you to the correct diagram as soon as i find it.

 

Thanks. Like I said, I wasn't sure and I just didn't understand it. I think I do a lot more now.

 

Quick question for you acrimonious, in your circuit, can you replace the 3 relays with mosfets? They cheaper and have no moving parts.

 

No, they wont be able to switch to give you the 7V and they have a wattage limit.

 

Erm...I was looking at the circuit really hard when I had an idea. I'm not sure if it works, but here goes.

Would it be a problem if an output from the 4017 isn't connected to anything? If not, then I don't need an opto-isolator and relay for the "off" state. I can simply not connect anything to output 2 and just have two sets of relays etc.

Would this work?

 

A few more questions:

- What sort of Diodes do I need. I went to mappers and there are many types.
- With the relays, which type do I need between 12v Coil and 6v Coil?
- Do I need IC sockets for the 4017 and 40106?
- Does the ohm value have to be exactly 500, or will something close do? (Actually, should I use 500ohm for the Bl00 LEDs as well or replace with more suitable values?)

 

Your new circuit will not work as it has no off state (the fan(s) are always connected).

Diodes: i'd use a 1N4148
Relays: 5/6v coil
IC Sockets: Yes, its recomended
Resistor: Any value close to 500

 

OK. Thanks.

What I was thinking was that with my version of the circuit, if the 4017 was at output 2, then output 0 & 1 would be effectively off, and there would be no power to the optical isolators, therefore no power to the Relays. (I'm using 1 + 1 = 3 logic here )