stolzie
New Member
Hi Everyone,
I have got a problem that I am not sure how I can solve and need advice on possible solutions.
I have a actuator HK-DZT-03 that I am using to raise and lower a board. The actuator is shown in the following link.
**broken link removed**
The actuator is currently being driven from a relay (ACT512) which is switched via a ULN controlled via a PIC. The PIC also has a current sensing circuit which monitors the current draw from the actuator to determine if we have reached full travel when the limit switches are reached.
The problem that I am experiencing is that I am getting a massive spark across the relay contacts when the actuator stalls. I have tried to catch with firmware the increase current before the stall but it still happens every now and again. I am assuming it is counter EMF generated by the motor producing this spark.
I am thinking that I can either put a transorb or a varistor across the relay contacts to eleminate this counter EMF.
I have attached a basic example of the relay configuration.
How would I go about calculating the value I require? Are there set formulas to calculate this is is all hocus pocus?
Any help would be greatly appreciated.
Thanks,
Jason
I have got a problem that I am not sure how I can solve and need advice on possible solutions.
I have a actuator HK-DZT-03 that I am using to raise and lower a board. The actuator is shown in the following link.
**broken link removed**
The actuator is currently being driven from a relay (ACT512) which is switched via a ULN controlled via a PIC. The PIC also has a current sensing circuit which monitors the current draw from the actuator to determine if we have reached full travel when the limit switches are reached.
The problem that I am experiencing is that I am getting a massive spark across the relay contacts when the actuator stalls. I have tried to catch with firmware the increase current before the stall but it still happens every now and again. I am assuming it is counter EMF generated by the motor producing this spark.
I am thinking that I can either put a transorb or a varistor across the relay contacts to eleminate this counter EMF.
I have attached a basic example of the relay configuration.
How would I go about calculating the value I require? Are there set formulas to calculate this is is all hocus pocus?
Any help would be greatly appreciated.
Thanks,
Jason