Electronics question

[Orin2017]

Hi. I bought a RC model some years back which had a transceiver with two buttons: A and B. On the receiver, which seems limited to 9 Volts because 12 volts doesn’t work, I have two electricity pins (one for positive and one for negative) and then finally I have 6 pins, 3 for each relay switch. Each relay switch offers the following pins: NO1, COM, NO2, NC1, COM, NC2.

When I connect a 9 volt battery to the chip, a red led light lights up correctly, and depending upon what choices I select I can see and sometimes hear the relay switch working. My problem is that I don’t know what wires to connect to the relay switch. I guessed that I would connect to NC1 and NC2. This makes the relay switches emit led lights and a clicking sound. However, this does not open any 9 V electrical circuit. Can you tell me how to connect my wires to these switches in order to make the remote control work?

Also, I read that COM means COMMON. What is that even used for? I understand what NC and NO means but not com.

Any help is appreciated.

 

[MrTheHerder]

NO= Normally Open (open unless the button is pushed)
NC= Normally Closed (connected unless the button is pushed)
Com= Common (used for both NO and NC)

I find diagrams are easier to understand so hopefully this helps:


The relays are acting like a basic switch with 2 choices. One of them (NC) is active unless the button is pushed, then the other (NO) is active. So using the diagram above whenever the button is NOT pushed the red light is lit up. Once the button is pushed the red light will be disconnected from power and the green light will light up until the button gets let go again.

Without knowing your exact board that you've got its hard to say how things should be set up but I can make some guesses based on how other systems I've used worked.

First thing. If you're trying to use this for a remote firing system I would GUESS that what you want is to use NO1 and COM for Channel A and NO2 and COM for Channel B. Hooking up your e-match across NO choices will mean that no power will flow to it until you press the button.

Second: Relays typically don't provide power on their own. A relay is just a simple switch that is controlled by electricity instead of you flipping a lever. The + and - terminals on your board are most likely just to run the receiver electronics and aren't actually proving voltage out of the relays. Because of that you will probably have to provide the firing circuit with power as well. Something like this :

The power supply listed there would be your 9v battery and then the board and the firing circuits would all be powered from one battery source. Press button A and one of the relays will close and fire the match. Press button B and the other will get power and fire.

 

[Orin2017]

NO= Normally Open (open unless the button is pushed)
NC= Normally Closed (connected unless the button is pushed)
Com= Common (used for both NO and NC)

I find diagrams are easier to understand so hopefully this helps:
View attachment 454

The relays are acting like a basic switch with 2 choices. One of them (NC) is active unless the button is pushed, then the other (NO) is active. So using the diagram above whenever the button is NOT pushed the red light is lit up. Once the button is pushed the red light will be disconnected from power and the green light will light up until the button gets let go again.

Without knowing your exact board that you've got its hard to say how things should be set up but I can make some guesses based on how other systems I've used worked.

First thing. If you're trying to use this for a remote firing system I would GUESS that what you want is to use NO1 and COM for Channel A and NO2 and COM for Channel B. Hooking up your e-match across NO choices will mean that no power will flow to it until you press the button.

Second: Relays typically don't provide power on their own. A relay is just a simple switch that is controlled by electricity instead of you flipping a lever. The + and - terminals on your board are most likely just to run the receiver electronics and aren't actually proving voltage out of the relays. Because of that you will probably have to provide the firing circuit with power as well. Something like this :
View attachment 455
The power supply listed there would be your 9v battery and then the board and the firing circuits would all be powered from one battery source. Press button A and one of the relays will close and fire the match. Press button B and the other will get power and fire.

Hi. Thanks a bunch for taking the time to answer. Really, a bunch. This tells me I need to use a com pin no matter what. Last night when I experimented with my options, I was unable to get a simple, tiny piece of nichrome wire to heat up. My remote control board is made for DC 9 Volts. Knowing that is enough to light a filament in a light bulb, I thought it would heat nichrome wire. I have the chemicals to add to nichrome wire to make it light on fire. So I had ordered like 5 of these RC units. Separately, I bought three RC units controlled by one remote and when those didn’t work for me I bought a long range RC consisting of two units and one remote. In my next post, I’ll describe the board.

 

[Orin2017]

This is my firing system.

 

[Orin2017]

So if I need to provide power to the relay switches, does mean I need to insert a jumper wire from the power supply to EACH relay switch? If so, a positive wire, or a negative wire? And if so, on the relay switch, which pin (or pins) gets the power?

 

[Orin2017]

I have visual spatial deficits. That means diagrams like the ones provided don’t sink in for me. What sinks in are written instructions. What I want to accomplish is an e-match (or nichrome wire) to activate when I press either button A or button B. See the picture I uploaded of the board and remote.
With that in mind, could you tell me what wires to connect to what pins? That’s how I will learn. After I see the wires in place, your diagram will make sense. I know that is bass-ackwards...but it is what it is.
I really appreciate the help.

 

[MrTheHerder]

I'll do my best to describe the wiring path so that it makes sense in words:

Here's how to wire just one of the sides. You can repeat the middle 3 steps for the 2nd side once you understand it.

First run a wire from from negative side of your battery to the negative terminal on your board.
From there take a second wire out of the negative terminal and run it to the COM port between NO1 and NC1
Run another wire out from the NO1 port. The other end of this wire will connect to one end of your ignitor whatever kind it is.
From the other end of the ignitor run a wire to the Positive terminal on the board
Lastly run a second wire from the positive terminal on the board to the positive side of your battery.

By doing this you have constant power to the board so that it can get signal from the remote. A second loop has the ignition source and relay acting as a switch. Once the relay is closed that second loop circuit closes and should fire your nichrome.


You mentioned testing your nichrome. To see if your 9v battery is enough to get it to heat you can just bridge a bit of the wire across the battery terminals for a short time. If it doesn't react like you're hoping you may need a higher voltage to get those wires to heat. I know people that have used nichrome in the past have mentioned that it can sometimes take a few seconds to "cook" before it gets hot enough to do the job. There are ways to do that with your system but they're a little more complicated so lets see if the 9v is enough to work first.

 

[Orin2017]

I'll do my best to describe the wiring path so that it makes sense in words:

Here's how to wire just one of the sides. You can repeat the middle 3 steps for the 2nd side once you understand it.

First run a wire from from negative side of your battery to the negative terminal on your board.
From there take a second wire out of the negative terminal and run it to the COM port between NO1 and NC1
Run another wire out from the NO1 port. The other end of this wire will connect to one end of your ignitor whatever kind it is.
From the other end of the ignitor run a wire to the Positive terminal on the board
Lastly run a second wire from the positive terminal on the board to the positive side of your battery.

By doing this you have constant power to the board so that it can get signal from the remote. A second loop has the ignition source and relay acting as a switch. Once the relay is closed that second loop circuit closes and should fire your nichrome.


You mentioned testing your nichrome. To see if your 9v battery is enough to get it to heat you can just bridge a bit of the wire across the battery terminals for a short time. If it doesn't react like you're hoping you may need a higher voltage to get those wires to heat. I know people that have used nichrome in the past have mentioned that it can sometimes take a few seconds to "cook" before it gets hot enough to do the job. There are ways to do that with your system but they're a little more complicated so lets see if the 9v is enough to work first.

Thank you for the awesome reply. It made perfect sense of everything. Unfortunately it did not work, but it made sense. I tried to use an ematch and it didn’t work. I tried to put the wires on my tongue and and did not get any shock the way I did with the 9Volt source battery. I tried the same wiring on a separate unit and got the same results. So I am thinking I must have made a mistake in ordering these things. It wasn’t advertised as being for pyrotechnics. Perhaps I inadvertently ordered something that won’t work for my intended purpose.

 

[MrTheHerder]

Can you take a picture of one of them wired up? That will help me see if something got crossed.
Also if they came with a manual that would be helpful as well.

Just because they weren't marketed as being used for fireworks doesn't necessarily mean it won't work. My first 12 cue firing system was using a relay board from ebay that wasn't in any way marketed for fireworks but it worked fantastically.

I took a moment to look at the photo of the board you posted and it looks like the relays are designed for 12v DC. 8 standard double A batteries will get you to 12v or you can use any other 12v battery like those found it most remote controlled toys these days. Getting the voltage up to 12v instead of only 9 from your current battery might help the relays close more reliably.

 

[Orin2017]

Thanks again for the helpful reply. I bought these gadgets years ago and I don’t remember who or where I bought them from. There is no manufacture’s name, or a model or serial number, i.e., these are Chinese. I probably bought them on ebay. I will take a picture of these wired up and it to you. As for the 9V V. 12V issue, I can only tell you what I experienced several times: when I use 12 volt batteries, the red light does not light up on the circuit board; however, the red light does light up using the 9V battery source, which leads me to believe it was made for 9 volts.

 

[Orin2017]

Here are the pictures of the board, wired up.

 

[Orin2017]

By the way, the e-match or talon ignitor or whatever that is that I have wired up to this board in this picture does work (or did work). I removed it from this board and attached it to a different type of remote control system (an AN01 Firing System Sold by CaryMart), and it ignited the second I hit the button. I tested the nichrome wire on a different 9Volt battery and it burned red immediately. I tested the battery used in the picture and it only sizzled and smoked a little, indicating the battery could be to blame. I hate to waste good e-matches but I’ll try attaching a new one to definitively tell whether the battery was the problem all along. Yep! Holy Cow! By God, you did it! That’s all it was: the battery was not strong enough!

 

[Orin2017]

Now that we solved the wiring problem, my next question is whether I can re-use the type of igniter used in this picture. I am new to this so I don’t recall if this is called an e-match or a talon igniter or what it is called. Regardless of what it is called, can I reuse it? Before I used it, it “looked“ like the end was dipped in black powder and then, once dry, dipped again in nitrocellulose lacquer. I happen to have nichrome wire, black powder and NC lacquer so it would be a joy to me if other people reuse theirs. The tip has a metal end soldered to 22 gauge wire.

 

[MrTheHerder]

Glad the new battery got everything working for you.

As for re-using that ematch you really can't. Once the match fires the bridge wire on that chip burns up completely and makes the whole thing useless. Some people will cut off the burnt up end and use the wires for making their own matches with, but at that point all you have is a convenient piece of wire to build off of.

 

[Orin2017]

Glad the new battery got everything working for you.

As for re-using that ematch you really can't. Once the match fires the bridge wire on that chip burns up completely and makes the whole thing useless. Some people will cut off the burnt up end and use the wires for making their own matches with, but at that point all you have is a convenient piece of wire to build off of.

Thank you. I have the chemicals to use to make e-matches; I just haven’t done it yet. I read an article on Skylighter about using a piece of microchip in between both wires. A microchip isn’t feasible for me. But I have all of the chemicals necessary. My town lacks a Radioshack. What do other people use? Should I create a separate thread for that question?