Need help! Want to modify heated blanket controller to turn on when plugged in

Thread Starter

Jared Dickinson

Joined Jan 2, 2018
6
Hello! I have a very primitive understanding of circuitry and can't seem to find an answer to my question online due to my lack of knowing what to search for.

Simply, I have a heated blanket that I want to be able to turn on by switching on the power to my surge protector (wifi-enabled).

When I turn on the power, it takes a second step of pressing the button on the heated blanket controller in order to turn on the heat.

What is closing the circuit when I turn off the power source and then turn it back on using the surge protector?

Is there a way to modify the circuitry to accomplish what I am hoping to?

15149502963941078089570.jpg 15149503766591150148089.jpg 15149502963941078089570.jpg 15149503766591150148089.jpg
 

AlbertHall

Joined Jun 4, 2014
11,211
I presume that different power levels can be selected by pressing that button as there are the three LEDs?
If you want it to switch on to the highest power setting then it might be as simple as shorting the main terminals on the triac (MT1 and MT2).
Before you try that, you should check that on the highest power setting that the voltage going to the heater is the same as the supply voltage being fed to the board.

Also it is possible that you may lose the overheating protection. It looks as if there are three wires coming from the heating element - the white and green are fed with power controlled by the triac, but the black wire feeds into the control circuit and may be connected to a temperature sensor within the blanket and shorting the triac will disable any control from the temperature sensor.
 

bushrat

Joined Nov 29, 2014
209
So what happens when you press the button? Does the button turn on when the button is pressed or does it turn on after you release the button?
 

Thread Starter

Jared Dickinson

Joined Jan 2, 2018
6
I presume that different power levels can be selected by pressing that button as there are the three LEDs?
If you want it to switch on to the highest power setting then it might be as simple as shorting the main terminals on the triac (MT1 and MT2).
Before you try that, you should check that on the highest power setting that the voltage going to the heater is the same as the supply voltage being fed to the board.

Also it is possible that you may lose the overheating protection. It looks as if there are three wires coming from the heating element - the white and green are fed with power controlled by the triac, but the black wire feeds into the control circuit and may be connected to a temperature sensor within the blanket and shorting the triac will disable any control from the temperature sensor.
You are correct, there are 3 power settings. The blanket turns on to the lowest setting after the first bottom press (upon release), then medium, then high. This is a spare blanket so I am willing to take a chance on destroying it. Which are the main terminals on the triac? I'll be testing this under supervision before I put it to use so I will be able to tell if it overheats due to a disabled temp sensor.
 

AlbertHall

Joined Jun 4, 2014
11,211
The blanket turns on when the button is released.
You might be able to get it to turn on to the lowest power setting by connecting a capacitor across the switch. When first switched on the capacitor will be discharged and will look like the button is pressed. The capacitor will charge and then look like the button is released. You would need to experiment with the value of the capacitor. This may not work as the circuit may expect the switch to be open at switch on.
 

AlbertHall

Joined Jun 4, 2014
11,211
You are correct, there are 3 power settings. The blanket turns on to the lowest setting after the first bottom press (upon release), then medium, then high. This is a spare blanket so I am willing to take a chance on destroying it. Which are the main terminals on the triac? I'll be testing this under supervision before I put it to use so I will be able to tell if it overheats due to a disabled temp sensor.
The terminals to short together are circled in the attached image.
BUT do check that on the highest power setting that the heater voltage equals the mains voltage. The heater may not be designed to run at the full mains voltage which is what will happen when the triac is shorted.
 

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Thread Starter

Jared Dickinson

Joined Jan 2, 2018
6
The terminals to short together are circled in the attached image.
BUT do check that on the highest power setting that the heater voltage equals the mains voltage. The heater may not be designed to run at the full mains voltage which is what will happen when the triac is shorted.
I shorted the two terminals together and it worked, after a few nights of watching the blanket while it was on, I determined that it was consistent and safe. Last night we used our Google Home to turn on our heated blanket through the wifi enabled surge protector and had a timer shut the switch off after an hour. It was so nice to fall asleep with the heated blanket and be able to use the timer to turn it back on again around the time I wake up. Thanks so much for your help! My next project will be installing a remote car starter in my fiancee's car and attempting to integrate the remote into one of the wifi switches to allow us to start the car using a timer or by asking our Google Home! Wish me luck!
 

Lyonspride

Joined Jan 6, 2014
137
I shorted the two terminals together and it worked, after a few nights of watching the blanket while it was on, I determined that it was consistent and safe. Last night we used our Google Home to turn on our heated blanket through the wifi enabled surge protector and had a timer shut the switch off after an hour. It was so nice to fall asleep with the heated blanket and be able to use the timer to turn it back on again around the time I wake up. Thanks so much for your help! My next project will be installing a remote car starter in my fiancee's car and attempting to integrate the remote into one of the wifi switches to allow us to start the car using a timer or by asking our Google Home! Wish me luck!
I don't know where you are, but I know in the UK it's illegal to leave a vehicle with the engine running in a public area (anywhere accessible to the public), there's quite a hefty fine. You must be "In control of the vehicle at all times when the engine is running".

Additional to that, if something goes wrong at starting (like cambelt the snaps) the driver can shut the engine down before too much damage occurs.
 
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