Eliminate touch switch

Thread Starter

mfrsh

Joined Feb 12, 2023
3
Does anyone know how to eliminate the touch switch on this board so the unit turns on when power is supplied. It belongs to a humidifier that i would like to be able to plug into an environmental controller. The touch switch coil 20230212_014136.jpggoes to pin 12 on the ic. Thanks.
 

MaxHeadRoom

Joined Jul 18, 2013
28,688
The one connected to R3?
If it is just simple contact closure, you could place a small sensitive relay in series with a electrolytic cap in order for it to pulse on.
 

Thread Starter

mfrsh

Joined Feb 12, 2023
3
The one connected to R3?
If it is just simple contact closure, you could place a small sensitive relay in series with a electrolytic cap in order for it to pulse on.
The coil is connected to r23 which goes to pin 12. Is there a transistor of sorts in the ic which makes the actual switch?
 

MaxHeadRoom

Joined Jul 18, 2013
28,688
The coil is connected to r23 which goes to pin 12. Is there a transistor of sorts in the ic which makes the actual switch?
I corrected it, it meant to be R23.
I understood it was done manually?
What is R23 connected to ? Is that the touch switch?
 

Thread Starter

mfrsh

Joined Feb 12, 2023
3
I corrected it, it meant to be R23.
I understood it was done manually?
What is R23 connected to ? Is that the touch switch?
Yes the touch coil is the 3 leads that run to r23 which run to pin 12. Also I'm not sure a pulse would work because the unit does a short power cycle as soon as you plug it in and then you are able to actually power it on. The pulse would happen at the same time and would be a second or two too soon. I'm not a tech or an engineer. I have worked in assembly, so I don't have extensive knowledge of the components ot the circuitry but a basic knowledge. Thank you.
 
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