Jonasx said:
I have some power car seats to mount and make functional in my house.
How do I power these? I was thinking of just using a 12 volt power supply. These being DC motors (12 volt i'm assuming). Is there any special consideration you can see in doing this? I plan on using a junction type box to dole out the power to each of the motors (4 in each counting the lumbar). As these seats were kinda price I don't want to burn out the motors in them. I guess what I really need to know is how do amps relate in this application.
Standard auto power seats are nominal 12VDC devices, with reversing normally being handled by the switch arrangement. In most American autos, the power seat circuit is usually protected via a 20A self-resetting (thermal) circuit breaker, though I have seen some with 30A ratings.
Why don't you simply apply power to the seat motor(s) and measure the current draw? Bear in mind that the curent draw will be somewhat higher if there is someone actually sitting on the seat, so that is the best way to check the draw!
I remember a problem years ago when I was a Ford service manager. The customer, a petite woman, complained that the power seats in her new Lincoln would not work reliably for a while, and then would quit altogether. The tech assigned to the job found a failed (open) circuit breaker -- unusual, but not unheard of. The CB was replaced and the car was returned to its owner. A couple of weeks later, it was back with the same problem, same cause, same solution. This time, we measured current draw on all of the motors, and found nothing amiss, so the car was again returned to its owner. As you might have guessed, it was back a third time with the same problem. This time, the customer was making lawsuit noises -- three times, same problem etc. , and we were hard-pressed for a solution. In duscussing the problem with her at length, it was mentioned that she had no problems until the seat quit working entirely. It was her husband who was having the continual seat problems. I politely asked her if it was possible to have her husband "stop down so that I could chat with him". What I really wanted was to see him... to see if my SWAG as to the cause was right. It turned out that I was right! Her husband weighed almost 450 lbs! His weight on the seat was considerably more than the Ford engineers had anticipated, and was causing such excessive current draw that the breaker would continually trip and reset when he adjsuted the seat. Of course, this would continue until the breaker cycled itself to death. Needless to say, that was a tough one to explain in a polite manner...