Push to ON push to OFF circuit

Hi, I want to build a PUSH to ON/OFF circuit using CD4027. I have two voltages. 3v & 8.5v
I want the circuit to work on 3v and drive a 5v relay at output.
Can anyone help me for this circuit?

Questions:
# You "have" 8.5v? Yet you want it to work with 3v? So, what is the role of the 8.5 volts? Why even mention that?
# Will your 5v relay work at 3 volts? How much current is needed to drive the relay at 3v or 5v? OR what is the relay coil resistance?

If you require this to work at 3 volts, and the 8.5v supply is not an option, then you might need to do DC-to-DC conversion. Otherwise, this is how I interpret what you are saying:

Use the 3v supply to drive the switch and CD4027 and have the Q or Q-bar output drive a transistor that drives the relay coil via a 5v supply driven by the 8.5v source. In other words, the 8.5v source feeds a 5v regulator that drives the relay coil via the "open-collector" transistor circuit. This, of course, is assuming that the 8.5v supply can deliver enough current to drive the relay coil.

If it must all work from the 3v supply, then, again, the 3v supply must be capable of driving the relay coil, whether that's directly, or via a DC-to-DC converter.

That attached schematic is merely to present the logic. I'll leave the voltage levels to you.

Oops, got that circuit wrong. The attached is the corrected version...

Thanks for your reply,and the circuit.
Can I swap the switch and R1 ?As I want the switch from the positive edge.

Can I give 3v to the IC and 8.5v to relay through 7805?and the other end to the transistor?

And how to filter the debounces at the CLK input of the IC4027?

Oops, my brain was AWOL--probably too much "holiday cheer"! I attached a new circuit. The Schmitt trigger (74AC14) conditions the push button signal into a sharp edged waveform to prevent excessive current draw in the 4027 (otherwise, as the capacitor (C1) discharges through R1, the 4027 would be driven into it's active region). I put two schmitt trigger inverters in series to provide a rising edge to the clock input upon "press" rather than "release". Adjust as needed. You can try it without the schmitt trigger, but I wouldn't recommend it.

The only way around having to use the input conditioning circuit (R1, C1, IC2a, IC2b) is to use a double pole, single throw push button and wire it to the S/R inputs of the 4027.

Hi, Thank you very much for this circuit.
I tried the previous circuit and it worked very good,but there are two problems.
I think the one would be solved by the new circuit.
The second is,
I am using this circuit as add on circuit to SONY PS2 video game console.
I am taking the 8.5v and 3v supply from the joystick controller of the video game.
But when I operate this circuit,the joystick controller is disconnecting from the video game console for a fraction of seconds and connects again.
Can you give me any suggestion for this problem?

What do you mean by "disconnecting"? Is there some physical connection that's breaking, or is some voltage dropping momentarily, or what?! It would be really nice if you would provide more detailed descriptions. Like, for instance, it would have been really cool if you had mentioned all that stuff about the joystick controller and such in your first post!

And, you still haven't given me any specs on that relay.

I am using 2 relays paralleled by a BC547 transistor.
The relay is a 5v DPDT relay 167 ohms
http://www.datasheetcatalog.org/datasheets2/15/150649_2.pdf
I am unable to explain about the problem, but the joystick is based on a micro processor and some sort of disturbance is happening while pressing the push to on switch. I think there is no problem with our circuit.

OK, here's how you provide detail. Rather than saying "some sort of disturbance", tell me how you came to that conclusion, i.e. what is happening, exactly--what does the disturbance look like--what _tells_ you there is a "disturbance"?

But, I'll offer this (a shot in the dark): perhaps the relay is drawing more current than the 8.5v supply can deliver. Try using an external power supply to supply the 8.5 volts and see if the "disturbance" goes away.

Also, the BC547 has a typical beta of 120 at 100ma. The two relays will be drawing something like 60ma. 60/120 = 0.5ma. That's probably more than the 4027 can deliver. So, two things:
# The relay might not be getting enough drive current.
# The 3 volt supply might be getting pulled down by the transistor (unable to supply that .5 ma base current.
# If you didn't already, try putting a 01nF cap across the VDD and GND pins on both the 4027 and the 74AC14.

Oops, that should be "10nf" across the VDD and GND pins.

I tried this circuit with only an LED.
The same problem occurred.

Thank you,will try the circuit tomorrow and check the results.

The LED might, also, be drawing too much current. You need to find out how much current each of these supplies can handle. Try using a potentiometer with a current meter and volt meter to see how much current you can draw before the voltage starts to drop.
Be sure to start with a high resistance and then slowly lower it until the voltage starts to dip. Make note of that current--it's the maximum. Also, see if you can cause your "disturbance" with the pot--cautiously (you probably don't want to burn out either of these supplies).

Hi, The circuit is perfectly alright.
There was a component fault for the disturbance.
Now the circuit is perfectly ok without 74ac14 IC.
I am very thankful to you for your guidance and for the circuit.
My name is RAJU and I am from INDIA.
How can I contact you in future for ......

Great. I'm glad I was of help. Future contact via EEWeb would be fine.

Hi, How can I use 3v relay at 4027 output instead of using a 5v relay?
I want to use the whole circuit to run on 3v. What components shall I use to drive a two 3v relays at 4027 output.

When I operate the switch SW1, the 3v is getting short and some disturbance is occuring to the circuit from where I am taking the 3v supply. But this circuit is working perfectly.

It is not so difficult to which you think, i think you should try to make this , you'll be success in that

to run the whole thing on 3 volts (with a 3V relay) simply drive the relay from the 3 volt supply. Be sure, though, to isolate the relay supply line from the rest of the 3V supply feeds (i.e. run separate lines to the source, so the relay current isn't travelling down the same line that supplys the logic ICs. Also, place 10nF caps across the supply lines on the ICs (as close to the supply terminals as possible).

Hi, Can you tell me the transistor number to drive two 3v relays of 65 ohms each.from the output of 4027

PN2222A

Hi, STEVE
The circuit is working correctly but I am using two circuits for the two fi=lip flops of 4027.
I am driving 2 relays of 3v 45 ohms in parallel through BC 337 to the 4027 out put.
But when one of the 4027 is working,the other is not working.
If the first part of 4027 is on activate position,the next part of 4027 is not working,and if I deactivate the first and operate the second half of the 4027, then the second is working.But both flipflops of the 4027 are not working simultaneously.
What would be the problem?

OK, shot in the dark: make sure all unused inputs are tied either low or high. And it wouldn't hurt to add a 10nF ceramic cap across all Vdd/Vss pins. Beyond that, you will have to be more specific than "not working".

What is it not doing? What is the failure mode, exactly?