Hello,
I have a DC motor: when powered with Ni-Cd 7.2V power pack, running with attached gearbox. Starting current drawn is 13A and then 6A after one second and is steady at this current drawn.
Now, I want to drive it by transformer. I got a 6Vx2 of 60VA one. With two 6A diodes to have full-wave rectification, 6800uF capacitor attached. The measured open output voltage is 8.4VDC. When connecting it to the DC motor, the measured voltage goes down to 5.5V and current drawn is 5.6A.
By calculation, only 5.5Vx5.6A=31W was used on the transformer and 5.5v is too low for the motor to run.
Did I get the wrong rating transformer? or what improvement can I make in order to get 7V in running motor?
Thanks in advance
I have a DC motor: when powered with Ni-Cd 7.2V power pack, running with attached gearbox. Starting current drawn is 13A and then 6A after one second and is steady at this current drawn.
Now, I want to drive it by transformer. I got a 6Vx2 of 60VA one. With two 6A diodes to have full-wave rectification, 6800uF capacitor attached. The measured open output voltage is 8.4VDC. When connecting it to the DC motor, the measured voltage goes down to 5.5V and current drawn is 5.6A.
By calculation, only 5.5Vx5.6A=31W was used on the transformer and 5.5v is too low for the motor to run.
Did I get the wrong rating transformer? or what improvement can I make in order to get 7V in running motor?
Thanks in advance