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Looking to build a simple solution to control 12v amp trigger

catalogguy

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I have an amp with a 12v input trigger but I have no device with an output trigger. I have kind of been through the ringer looking for a reasonable solution and maybe this is the ticket. I would very much like to hear from someone who is comfortable with electronics to confirm that this looks like a safe and effective way to go.

This is a device on Amazon for $12.99 that include a 12v power adapter, a remote control and a control box. As far as I can see, this will
(1) provide the low level 12v output to supply current to the amplifier trigger input
(2) allow on/off control with the included IR remote (so I am counting on programming my Harmony remote)
(3) has the IR receiver on a flexible lead so I can try to position it best line-of-sight.

Price seems reasonable. I am not sure about that connector, but I suppose I can try to find something to plug into it or just cut it off.

Amazon.com: Clordeal 12V Power Supply, 44key Wireless IR Remote Control + Control Box + 12V 5A LED Transformer for SMD 3528 5050 RGB Led Strip Lights

1623878025403.png
 
How about something like this: https://www.amazon.com/DEWENWILS-El...te+control+power+socket&qid=1623878327&sr=8-5

In combination with a 12v PSU: https://www.amazon.com/500mA-Power-...=12v+power+supply+500ma&qid=1623878493&sr=8-6

You'll need an adapter like this for the trigger: https://www.amazon.com/CGTime-3-5Po....1mm+Female+DC+Adapter&qid=1623878601&sr=8-20

Alternatively, if your're happy to do a bit of soldering, you could cut off the existing DC plug and use a mono 3.5mm jack: https://www.amazon.com/Fancasee-Rep...m+Male+jack+mono+solder&qid=1623878779&sr=8-3

You may find some of that stuff cheaper on Ebay, or DigiKey, Mouser, etc.
 
Thanks for finding that. Is the remote IR? My concern is that if the remote requires RF, then I will not be able to program my Harmony remote.
Looks like RF to me - most of that style are so that they still work when out of sight. IR ones exist, but I don't think I'd trust any of the mains ones I've seen. You might have more luck than my quick search though. Searching for infrared switch will get you a load of relay modules that can switch 12V (although you would have to wire them up) and a few of the mains ones. The biggest problem with your original choice is probably making sure it doesn't accidentally end up dimming, which may cause problems with the device you're wanting to trigger.
 
How about this https://emotiva.com/products/et-3
Not ir or rf but manual turn on
Thanks... I looked at that to see how I could make it work. It is an interesting device but does not provide a control for switching the amp on and off.

I have come up with a few conceptual ways to do it. I am going to try something that incorporates and IR receiver into a 12v relay so that pressing On with the universal remote will just power on one more device, and that device will send the 12v signal to the amplifier.

I bought the gizmo in the post at top and confirmed that it is outputting 12v and is controlled by the included remote. I need to find a way to attach the trigger plug (3.5mm) to the gizmo. Not quite sure how to do that. I may start a new thread looking for soldering tips or wiring help!

Thanks so much for the input.
trigger 2.jpg
trigger 1.jpg
 
Do you have a multimeter or volt meter?

You need to check to see what output you get from the pins, if you connect them in parralel for example, and adjust the settings on the controller can you get more than 12v? In which case you might need to use just the ground and one positive, but ensure that the setting for whichever colour, R G or B that correlates to is set to maximum. I'm not entirely sure how these RGB signals work, it could be voltage, current or it might be PWM, pulse width modulation.

I'm guessing the pin/socket with the arrow mark is ground, the other three will be +ve and the voltage will vary according to the RGB signal. If you want to use this purely as an on-off control, you may be able to connect to those in parralel, like this:

1624012205134.png


You'll also need to check which wire is connected to the tip of the jack plug, I would guess that it's the red wire, but that's not guaranteed.

Maybe some help?: https://www.circuitbread.com/tutorials/how-rgb-leds-work-and-how-to-control-color
 
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This is what I did

https://www.audiosciencereview.com/...ed-dsp-dac-streamer.18681/page-43#post-803789

The relay I bought comes with its own remote, but it was programmable, so I am able to use my preamp remote to turn both on at the same time. I also programmed the relay to turn off with the mute button.

edit: it looks like this specific relay is sold out, but you can find others that have similar functionality. You may also be able to find it on ebay
 
This is what I did

https://www.audiosciencereview.com/...ed-dsp-dac-streamer.18681/page-43#post-803789

The relay I bought comes with its own remote, but it was programmable, so I am able to use my preamp remote to turn both on at the same time. I also programmed the relay to turn off with the mute button.

edit: it looks like this specific relay is sold out, but you can find others that have similar functionality. You may also be able to find it on ebay

This looks great! I had expected to use something more like your device until I found the other gizmo that seems to get me a little closer to a finished item with the enclosure, etc.
 
Do you have a multimeter or volt meter?

You need to check to see what output you get from the pins, if you connect them in parralel for example, and adjust the settings on the controller can you get more than 12v? In which case you might need to use just the ground and one positive, but ensure that the setting for whichever colour, R G or B that correlates to is set to maximum. I'm not entirely sure how these RGB signals work, it could be voltage, current or it might be PWM, pulse width modulation.

I'm guessing the pin/socket with the arrow mark is ground, the other three will be +ve and the voltage will vary according to the RGB signal. If you want to use this purely as an on-off control, you may be able to connect to those in parralel, like this:

View attachment 136308

You'll also need to check which wire is connected to the tip of the jack plug, I would guess that it's the red wire, but that's not guaranteed.

Maybe some help?: https://www.circuitbread.com/tutorials/how-rgb-leds-work-and-how-to-control-color

Thanks for bringing this up as I have had concerns. I measured the output from the barrel connector on the adapter at 12.5v DC. I got the same measurement at the pins coming out of the controller. I simply used the on/off power button on the remote (no colors or dimming, etc.).

Is it certain that the tip of the 3.5mm plug is to be positive?

The controller included this diagram:
controller.jpg
 
Do you have a multimeter or volt meter?
You'll also need to check which wire is connected to the tip of the jack plug, I would guess that it's the red wire, but that's not guaranteed.

Confirmed that the tip of the jack plug connects to the red wire.
 
I looked around for something to do this job but didn't find anything exactly right.

I bought an IR learning relay from eBay which came without instructions. In my fiddling with it's only button I managed to get it to learn a remote code. But only to toggle the state, not discrete on and off codes. The seller did not get back to me when I asked for docs.

So I decided to make one myself using an Arduino Nano clone and a relay module designed for 5v logic. I put it all in an IR transparent box and powered it all from a USB charger. My Hypex based amps don't actually need 12v, they are quite happy turning on with 5v.

It's a bit of a faff to get around the fact that nothing on eBay seems to have documentation, but not that hard. If anyone's interested I can list the parts used later (when I am at my PC rather than on the phone).
 
I looked around for something to do this job but didn't find anything exactly right.

I bought an IR learning relay from eBay which came without instructions. In my fiddling with it's only button I managed to get it to learn a remote code. But only to toggle the state, not discrete on and off codes. The seller did not get back to me when I asked for docs.

So I decided to make one myself using an Arduino Nano clone and a relay module designed for 5v logic. I put it all in an IR transparent box and powered it all from a USB charger. My Hypex based amps don't actually need 12v, they are quite happy turning on with 5v.

It's a bit of a faff to get around the fact that nothing on eBay seems to have documentation, but not that hard. If anyone's interested I can list the parts used later (when I am at my PC rather than on the phone).
I thought of using a pi that i have lying around, with an ir receiver hat. But as far as i know, pi can only control the 3.3v pins, not 5v. So i never tried that solution.
 
The Nano clones cost about £5 and give 5v lines. A TSOP17xx IR receiver can be directly attached. The relay boards for Arduino's are also very cheap. The software is basically the SimpleReceiver example from the IRremote library with a few extra lines. The hardest bit about the whole thing is making all the connecting wires without a crimp tool! I really must buy a crimp tool.

Just to give you an idea, this is (most of) the code:

C++:
/*
 * SimpleReceiver.cpp
 *
 * Demonstrates receiving NEC IR codes with IRrecv
 *
 *  Copyright (C) 2020-2021  Armin Joachimsmeyer
 *  [email protected]
 *
 *  This file is part of Arduino-IRremote https://github.com/Arduino-IRremote/Arduino-IRremote.
 *
 *  MIT License
 */

/*
 * Specify which protocol(s) should be used for decoding.
 * If no protocol is defined, all protocols are active.
 */
//#define DECODE_DENON        // Includes Sharp
//#define DECODE_JVC
//#define DECODE_KASEIKYO
//#define DECODE_PANASONIC    // the same as DECODE_KASEIKYO
//#define DECODE_LG
#define DECODE_NEC          // Includes Apple and Onkyo
//#define DECODE_SAMSUNG
//#define DECODE_SONY
//#define DECODE_RC5
//#define DECODE_RC6

//#define DECODE_BOSEWAVE
//#define DECODE_LEGO_PF
//#define DECODE_MAGIQUEST
//#define DECODE_WHYNTER

//#define DECODE_HASH         // special decoder for all protocols

#include <Arduino.h>

/*
 * Define macros for input and output pin etc.
 */
#include "PinDefinitionsAndMore.h"

#include <IRremote.h>

const int RELAY_PIN = 3;

void setup() {
    Serial.begin(115200);
    // Just to know which program is running on my Arduino
    Serial.println(F("START " __FILE__ " from " __DATE__ "\r\nUsing library version " VERSION_IRREMOTE));

    /*
     * Start the receiver, enable feedback LED and take LED feedback pin from the internal boards definition
     */
    IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK, USE_DEFAULT_FEEDBACK_LED_PIN);

    Serial.print(F("Ready to receive IR signals at pin "));
    Serial.println(IR_RECEIVE_PIN);

    pinMode(RELAY_PIN, OUTPUT);
    digitalWrite(RELAY_PIN, HIGH);
}

void loop() {
    /*
     * Check if received data is available and if yes, try to decode it.
     * Decoded result is in the IrReceiver.decodedIRData structure.
     *
     * E.g. command is in IrReceiver.decodedIRData.command
     * address is in command is in IrReceiver.decodedIRData.address
     * and up to 32 bit raw data in IrReceiver.decodedIRData.decodedRawData
     */
    if (IrReceiver.decode()) {

        // Print a short summary of received data
        IrReceiver.printIRResultShort(&Serial);
        if (IrReceiver.decodedIRData.protocol == UNKNOWN) {
            // We have an unknown protocol here, print more info
            IrReceiver.printIRResultRawFormatted(&Serial, true);
        }
        Serial.println();

        /*
         * !!!Important!!! Enable receiving of the next value,
         * since receiving has stopped after the end of the current received data packet.
         */
        IrReceiver.resume(); // Enable receiving of the next value

        /*
         * Finally, check the received data and perform actions according to the received command
         */
        if (IrReceiver.decodedIRData.protocol== NEC) {
            if (IrReceiver.decodedIRData.command == 0x40) {
                // Turn on relay
                Serial.println(F("Relay On."));
                digitalWrite(RELAY_PIN, LOW);
            } else if (IrReceiver.decodedIRData.command == 0x19) {
                // Turn off relay
                Serial.println(F("Relay Off."));
                digitalWrite(RELAY_PIN, HIGH);
            }
        }
    }
}
 
This is working great! I confirmed that the "arrow" was positive. I simply inserted the wires from the mono plug into the controller plug and taped it up. I taught the Harmony the power on/off from the remote that came with the controller. The amp powers on and off with the streamer for music or with the TV and cable box or TV and DVD, etc. I really appreciate all the help I received.
trigger 5.jpg
 
I'm in lock down limbo so my project to add a 12v trigger had stalled but the local electronics store has gone click and collect. This is my project:

Streamer
Rpi 4 in an Argon40 case, Argon ONE Case.
The case has an on/off button. With the Argon scripts loaded it will de-power on shutdown, an important requirement.
Shutdown is either via the button or browser.
It includes a fan but the case has excellent thermal characteristics so the fan can be disabled.
Works with Volumio and MoOde.

DAC
D10 balanced.
The DAC is powered by the USB port.
The DAC mutes it's output during power on/off. No loud, speaker destroying, pops; unlike the Khadas tone card.

Amps
2 x mono blocks with 12V trigger in jacks.

Trigger Extender
Emotiva 12 V trigger ET-3 Trigger.
Cons - Ridiculously bright blue LEDs, no galvanic isolation on the trigger in, US style power plug pack - annoying but fixed with an AU adapter and expensive after shipping costs and converting to $AU.
Pros - The trigger in will operate at 5 V, 3 x trigger outs, steel case - just heavy enough not slide around on the table and it has an override button - handy for testing.

Trigger Cable
USB to interchangeable plug Jaycar. It's a right angle connector, I will probably make another cable eventually.

The operation is simple. The ET-3 trigger in is connected to a spare usb port on the Rpi using the usb trigger cable. A trigger out on ET-3 is connected to the monoblocks' trigger in using standard 3.5 mm cables.

When the Rpi powers up, +5 V is applied to trigger in on the ET-3. The trigger outs go high, turning on the amps. When I power down the Rpi, either via the GUI or by pressing the button on the Argon 40 case, power is removed from the usb ports and the amps shutdown.

If I stand near the speakers I can hear a faint noise when the amps turn on. I was concerned about earth loops and noise due lack of galvanic isolation but so far so good.

Edited
 
Last edited:
Ah, I miss actually going into Jaycar.

My Pi setup can turn itself off remotely, but not back on. I'm hoping to just leave it on, and configure a relay to trigger the power amp on demand.

Failing that, I'm leaning towards one of these, which can power on/off its USB ports via an app. Turns off all the ports as a bank, so it's not ideal for keeping Pi on while powering amp up/down, but closest I can find so far.
 
Ah, I miss actually going into Jaycar.

My Pi setup can turn itself off remotely, but not back on. I'm hoping to just leave it on, and configure a relay to trigger the power amp on demand.

Failing that, I'm leaning towards one of these, which can power on/off its USB ports via an app. Turns off all the ports as a bank, so it's not ideal for keeping Pi on while powering amp up/down, but closest I can find so far.
At least I get to the Jaycar front door. I'm happy to turn the pi on in the morning. It's very handy not having to get out of bed at night. That's normally when I remember I have not switched the amps and streamer off. Now I just pick the smart phone.

I was looking some sort remote controlled power board. Theses Kogan devices might be the thing.
 
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