Regarding the overload and short circuit detection and protection in AC dimmer circuits

Vivek Reddy

Other Parts Discussed in Thread: MSP430G2553, DRV421, DRV411, DRV401, TMCS1101

Hi,

We have designed a LED dimmer circuit and working on improving the circuit to detect the overload and short circuit condition to protect the switching Mosfets and the load.

Do you have any overload and short circuit current detection IC's for load protection? or

Do you have any circuits suggestions for overload and short circuit detection from TI?

We are using MSP430G2553 as a controller in this design.

over 1 year ago

0 Javier Contreras4 over 1 year ago

TI__Mastermind 29710 points

Hello Vivek,

We have some device that may interest you. These are some current sense amplifiers with comparators.

https://www.ti.com/amplifier-circuit/current-sense/analog-output/products.html#3278=Analog%20output%20with%20integrated%20comparator&

0 Vivek Reddy over 1 year ago in reply to Javier Contreras4

Intellectual 565 points

Javier Contreras4

Thanks for your response. Sorry, I missed to mention our application voltage, here it is 230V AC.

But the IC's you rereferred are for the max. of 110V. Please help with the solutions for AC 230V application.

0 Javier Contreras4 over 1 year ago in reply to Vivek Reddy

TI__Mastermind 29710 points

Hello Vivek,

The only think I can think of for 230V AC is our magnetic current sense devices but I am not sure if the noise and range will work for you. I assume you are trying to measure the current on the AC mains side and not after you rectify the voltage. Also the range may be to low for this and the noise may be to large.

What is the range of current you expect?

https://www.ti.com/sensors/magnetic-sensors/hall-effect-current/products.html

If this could be an option please see this https://www.ti.com/lit/an/sboa518/sboa518.pdf.

We have other options but cost and size are normally not something for this application. These are the DRV401, DRV411, DRV421 which use a compensation core.

0 Vivek Reddy over 1 year ago in reply to Javier Contreras4

Intellectual 565 points

Javier Contreras4

The current range is 0-2A maximum (continuous). But there might be overshoots or undershoot in the current while controlling (dimming) the load.

The offset of the hall effect sensor is very high. Is this works for my application?

Please find the below schematic for your reference. It is a no neutral design. We need to sense the current in the line.

0 Javier Contreras4 over 1 year ago in reply to Vivek Reddy

TI__Mastermind 29710 points

Hello Vivek,

I would be concerned with the offset and noise and ambient field rejection but this depends on their requirements. I think the best device is the TMCS1101 or TMSC1100 for this. Look at the offset specifications to determine if it will meet your needs. Also I would pick the B4 version.

Regards,

Javier

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Regarding the overload and short circuit detection and protection in AC dimmer circuits