- Wed Mar 27, 2013 7:26 am
#157492
If the load can't move without power applied to the actuator, then there will be no regenerative braking, so you don't need a big series diode.
You're measuring 36V without a load because this is the peak voltage from the rectifier. With a load, this will drop. This is because your power supply is not regulated. If you put the big cap at the output of the rectifier, then it will charge to 36V and when you start the actuator, current will flow from the cap to the actuator until the capacitor voltage drops to 24V, then it will smooth the pulses from the rectifier.
Putting a resistor across the big cap is just a safety measure to allow the capacitor to discharge to a safe level when the power supply is off and there is no load.
Putting the cap across the LA terminals will cause an enormous current surge through the controller when it turns on. This will stress the controller as well as the bridge rectifier, and series diode if you use it. If you put the cap at the output of the bridge, there will be a surge when the supply is turned on but not through the controller. Diodes are usually spec'd to handle this turn on surge.
Heat sinking the rectifier is the most likely answer to the problem, without buying or building a properly designed regulated 24VDC power supply.
You're measuring 36V without a load because this is the peak voltage from the rectifier. With a load, this will drop. This is because your power supply is not regulated. If you put the big cap at the output of the rectifier, then it will charge to 36V and when you start the actuator, current will flow from the cap to the actuator until the capacitor voltage drops to 24V, then it will smooth the pulses from the rectifier.
Putting a resistor across the big cap is just a safety measure to allow the capacitor to discharge to a safe level when the power supply is off and there is no load.
Putting the cap across the LA terminals will cause an enormous current surge through the controller when it turns on. This will stress the controller as well as the bridge rectifier, and series diode if you use it. If you put the cap at the output of the bridge, there will be a surge when the supply is turned on but not through the controller. Diodes are usually spec'd to handle this turn on surge.
Heat sinking the rectifier is the most likely answer to the problem, without buying or building a properly designed regulated 24VDC power supply.