Hello Everyone,

Currently I have a small application were I am current a small solenoid (300 MA) over a small (12 V ,2 AMP but in reality it is more like 1 AMP) adaptor. When the solenoid starts working the over current protection of the adaptor kicks in (Turning the output on/off). The is not always the case, sometimes it works just fine. The solenoid needs the inrush current only for a few seconds. My question is can I disable the OCP in the adaptor, it seems that the protection is managed by an IC (DK 110) which seems to be a popular IC for adaptors management. I know that in my application turning the OCP is safe since it only operates for less than 10 Seconds.

I am attaching a photo of the adaptor PCB and a closer look for the IC.

Appreciate your great help as always

Thank you,

 

Probably not on that controller, its integral to the chip on the primary side. What's on the other side of the PCB?

 

Have you tried adding extra capacitance on the output?

 

Probably not on that controller, its integral to the chip on the primary side. What's on the other side of the PCB?

View attachment 323577

Hello Irving,

Thank you for your reply.
I was thinking that maybe I can override the whole IC thing, basically to have the output (12V) direct without any intervening from the IC.

I am attaching a photo for the back of the PCB.

Appreciate all your help.

Best regards,

 

Have you tried adding extra capacitance on the output?

Hi Ian,

I actually tried adding extra capacitance to both the input (AC) and output (DC) sides. Only the capacitance on the input side helped (A little bit) but it still did not do the trick. Especially when the AC input drops from 110V to 100V then the overcurrent protection gets worse.

Appreciate any ideas you could help with.

Best regards,

 

A capacitor across the opto's LED would delay its response to output voltage change. That might help the start-up. It might also have undesirable side-effects though.

 

Especially when the AC input drops from 110V to 100V then the overcurrent protection gets worse.

That is exactly what happens with this type of power supply.

 

The current sense is built in to the chip, it can't be altered on this chip series.

 

A capacitor across the opto's LED would delay its response to output voltage change. That might help the start-up. It might also have undesirable side-effects though.

Hello Alec,

I actually tried that and it delayed only the frequency (how fast the on/off protection happens) but still the same result more or less

 

The current sense is built in to the chip, it can't be altered on this chip series.

View attachment 323702

Hello,

I was hoping that there would be a way to bypass the whole chip, just simple 12V output with no protections or interventions from the chip.

 

I was hoping that there would be a way to bypass the whole chip, just simple 12V output with no protections or interventions from the chip.

This is how you brake things. The IC maker put in protection for a reason.
The "chip" is the heart of the power supply. Without it the output will be zero.
Get a bigger power supply.