Circuit for one input - multiple outputs

This is the place for any magazine-related discussions that don't fit in any of the column discussion boards below.
Post Reply
BLW_R/C
Posts: 5
Joined: Wed Jan 13, 2010 1:23 pm
Contact:

Circuit for one input - multiple outputs

Post by BLW_R/C » Wed Jan 13, 2010 1:38 pm

What i want to do is send a 5 volt signal from my radio (it will be controlled by a momentary switch) and i want to have my circuit toggle between a few different outputs. As an example i hit my switch the first time i get output 'A' i hit the switch again i get out put 'B' i hit the switch again i get out put 'C', so on and so on. I have the circuit that interprets the radio pulses and sends a steady 5 v dc signal when my switch is hit. I would like the outputs to be ether relays or NFETs. Any help would be awesome I think i really just need to be pointed in the right direction. Thanks for any help!!

User avatar
reloadron
Posts: 519
Joined: Sat Jun 28, 2008 8:57 am
Location: Cleveland, Ohio
Contact:

Re: Circuit for one input - multiple outputs

Post by reloadron » Wed Jan 13, 2010 3:45 pm

Welcome to the N&V Forums!

If I understand you correctly the easiest way to go about this would be with a micro controller. I assume each time you press a button on your transmitter it transmits a pulse for the duration of the button held to the receiver which outputs a high level (5 volts) for that duration. That pulse from the receiver could be sent to a uC which would count the pulses in and increment a counter +1 for each pulse. You don't mention when you would want a reset? How many times do you want to press the button and increment the count?

Another alternative would be just to input the pulses from the receiver to a counter like a 4017 Decade Counter / Divider. That would get you 0 through 9 and they could be cascaded for higher counts. I would buffer between the receiver and counter first stage.

Either way the outputs from the device would like drive a small transistor to drive your relays or as you mentioned put a MOSFET on each line to drive larger loads.

So you can get there using a uC or discreet components. Really depends on exactly what you want to do.

Ron

User avatar
dacflyer
Posts: 4540
Joined: Fri Feb 08, 2002 1:01 am
Location: USA / North Carolina / Fayetteville
Contact:

Re: Circuit for one input - multiple outputs

Post by dacflyer » Wed Jan 13, 2010 8:03 pm

a 4017 counter comes to mind, it has 10 outputs, you can use 2 chips to get 100 outputs.
your switch can be the pulse to advance it.. your switch would act as the clock input pulse.

not sure if it will work or not, but good luck.

BLW_R/C
Posts: 5
Joined: Wed Jan 13, 2010 1:23 pm
Contact:

Re: Circuit for one input - multiple outputs

Post by BLW_R/C » Thu Jan 14, 2010 9:07 am

Thank you both for your replies. Ron to be more specific with my question. I want to have one input, yes a high 5 volts, so the first time I send 5v it turns on "A" until I let it go. Then when I hit the switch again it would move to "B" until I let the switch go. And so on. This is going to be for a scale R/C helicopter. Military version that I want to be able to drop scale bombs for a show. I can do it with a bunch of different channels but would be best to just have one channel that controls all of them. I will add that the switch can stay on once activated that wouldn't be a problem. Dacflyer I will check into the 4017 and see if I can make that work, Thanks! And Ron I have never messed with uC but would be willing to could you point me in any one direction for ether a product , kit, book or all three. Thank you very much for you time!

User avatar
reloadron
Posts: 519
Joined: Sat Jun 28, 2008 8:57 am
Location: Cleveland, Ohio
Contact:

Re: Circuit for one input - multiple outputs

Post by reloadron » Thu Jan 14, 2010 12:10 pm

Hi Ya BLW

I would just run with a 4017 counter chip. Small and cheap. Later today when I get home I'll post a basic circuit for you. Each pulse from your receiver to the clock input will increment the counter up one count and you have 0 through 9 (10 counts total) if you added a second 4017 you could have up to 100 counts (0 through 99). Your release mechanism for your ordanance is your call. Everything would run off 5 Volts so what do you have available on your aircraft?

Ron

BLW_R/C
Posts: 5
Joined: Wed Jan 13, 2010 1:23 pm
Contact:

Re: Circuit for one input - multiple outputs

Post by BLW_R/C » Thu Jan 14, 2010 12:47 pm

Ron,

The power off the receiver is 5 volts and I would like to use that as the Pulse, the main battery is 23V. I looked up some 4017 circuits; Looks like it will work perfectly. I would like to see the circuit you suggest if it isn’t much work.

User avatar
reloadron
Posts: 519
Joined: Sat Jun 28, 2008 8:57 am
Location: Cleveland, Ohio
Contact:

Re: Circuit for one input - multiple outputs

Post by reloadron » Thu Jan 14, 2010 3:22 pm

You want to have your circuit something like this:

Image

There are no shortage of circuits out there for the old 4017 decade counter divider as you have discovered. The drawing was a quickie but here is how it works. Each pulse in from your receiver will increment the counter one count. That just means counter outputs Q0 through Q9 will take turns going high (5 Volts) at their output pins. I diod not show VCC for the chip but I would power the chip from 5 Volts. That is not a problem as you can use a little 7805 Voltage Regulator to take the 23 Volts you have and regulate to 5 volts. A Google of LM7805 or even 7805 circuits will bring up dozens of hits.

You see a line I have marked To N from pin 15. Pin 15 is the reset pin and will reset the counter to zero. Therefore if you want to count to 5 and reset on the sixth pulse, you would connect pin 15 to pin 5 of the 4017.

I used a single relay connected to pin 3 (Q0). If you want to count to whatever you would repeat the relays on the successive pins. The resistor is a 1 K Ohm 1/4 watt everyday carbon resistor. I did forget to place a diode across the relay coil to act as a snubber which would be added if you use relays. Any small generic 5 Volt coil relay (Radio Shack).

Pretty rough overview but if you have questions just ask.

Ron

BLW_R/C
Posts: 5
Joined: Wed Jan 13, 2010 1:23 pm
Contact:

Re: Circuit for one input - multiple outputs

Post by BLW_R/C » Fri Jan 15, 2010 7:36 am

Ron,

This looks perfict, thank you very much for your time!!! I'm going to get some parts on order today. Agian THANK YOU!

jimmy101
Posts: 82
Joined: Tue Mar 24, 2009 11:08 am
Contact:

Re: Circuit for one input - multiple outputs

Post by jimmy101 » Fri Jan 15, 2010 10:45 am

To get the circuit to turn off the output once the input signal goes off you could use a set of AND gates that takes the input signal and one of the output lines and ANDs them together. The output of the AND gate would go the the resistor and then to the power transister etc. You would need to find something like a quad 2 input AND gate chip.

Or, an even easier way, is to just skip every other output from the counter. The first output goes to the resitor,transistor,relay setup for the first chanel. The next, 2rd, output isn't connected to anything, the next (3rd) is connected to the next resistor,transistor, ...

When powered up, or reset, all output are off.
Pushing the button turns on #1 and the first circuit is activated.
When the button is released the #1 relay is still energized.
Push the button again and the counter moves forward to an output that is unconnected. All the relays are off.
Push again to activate the next relay.
Push again to turn that relay off.

BLW_R/C
Posts: 5
Joined: Wed Jan 13, 2010 1:23 pm
Contact:

Re: Circuit for one input - multiple outputs

Post by BLW_R/C » Fri Jan 15, 2010 1:55 pm

Jimmy 101,

Thanks good stuff.. Looks like the sky is the limit. I definitly came to the right place to get anwsers!

User avatar
reloadron
Posts: 519
Joined: Sat Jun 28, 2008 8:57 am
Location: Cleveland, Ohio
Contact:

Re: Circuit for one input - multiple outputs

Post by reloadron » Fri Jan 15, 2010 3:24 pm

Let us know how things go and if you need anymore help.

Ron

Post Reply

Who is online

Users browsing this forum: No registered users and 30 guests