motor control troubleshooting

Thread Starter

poposeed

Joined Jul 7, 2018
8
Hi,
Please help ,So I built up the circuit shown below . When motor is energized and running , lamp2 and lamp3 are on. Lamp1 goes off . The only problem I have is the motor is not running , however lamp2 is on and lamp 3 is on as expected. Lamp1 is off as expected .
1. I have checked and rechecked my wiring and I believe I have it wired correctly . What am I missing , or how do I go trouble shooting with a meter

note: ( I have replaced the motor with a one of those air bed pumps) Hooking these pump to power supply seperately fires it up so I know it works
 

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dendad

Joined Feb 20, 2016
3,921
Is the motor supposed to be in series with the lamp?
It could be the motor and Lamp2 should be in parallel.
If you answer Mr Al's questions it may help.
 

Thread Starter

poposeed

Joined Jul 7, 2018
8
Thank you for responding.
1. 120V led power
2. The (pump) I don’t have the specs on it. I am not sure what size motor was designed for this. The original question is uploaded below . I can answer the question theoretically but i wanted to see how the design actually work in real time .
In trying to troubleshoot it I have written down measurements I was getting from the meter . Hopefully it makes sense
 

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AlbertHall

Joined Jun 4, 2014
11,524
I suspect that this circuit wasn't intended to be built. It is just set up in order to ask the question about the logic effected by the relays. Whether the motor would work with a lamp in series would depend on the exact characteristics of the motor and lamp of which we have no knowledge and this has no relevance to the question being asked.
 

Thread Starter

poposeed

Joined Jul 7, 2018
8
Just as a follow up question, can someone please help me with a circuit I can build that will have a couple of relays (at least 3) , some push button switches , some LEDs, a buzzer, a fan , some dip switches? Or at least a link to where I can get such circuits .
Thank you in advance
 

GetDeviceInfo

Joined Jun 7, 2009
1,893
Your lamp 2 is acting as a current limiter, enough to prevent any torque developing in the motor. A high wattage low voltage lamp should solve that.
 

MrAl

Joined Jun 17, 2014
8,496
Hi,

Yes if the lamp is low wattage then the motor will never get enough current to start or even keep running it someone gave it a push.
A 100 watt 120vac bulb will allow more current to flow than the 100 watt value would indicate if the motor is low power, but not if the motor is high power, so we need to know that too.
A 100 watt 120vac bulb draws a bit less than 1 amp when running normally, so the motor would have to turn on less than 1 amp, even maybe much lower, or have a lower running voltage at nearly 1 amp.

In any case, it is best to know the motor rating and the lamp rating.
 

GetDeviceInfo

Joined Jun 7, 2009
1,893
Hi,

Yes if the lamp is low wattage then the motor will never get enough current to start or even keep running it someone gave it a push.
A 100 watt 120vac bulb will allow more current to flow than the 100 watt value would indicate if the motor is low power, but not if the motor is high power, so we need to know that too.
A 100 watt 120vac bulb draws a bit less than 1 amp when running normally, so the motor would have to turn on less than 1 amp, even maybe much lower, or have a lower running voltage at nearly 1 amp.

In any case, it is best to know the motor rating and the lamp rating.
Yes, sort of. In the motor/ lamp series circuit, your motor will require a minimum voltage drop across it to perform the task at hand. The remaining voltage, if available, is dropped across the lamp. 6, 12, 24 volt?
 

MrAl

Joined Jun 17, 2014
8,496
Yes, sort of. In the motor/ lamp series circuit, your motor will require a minimum voltage drop across it to perform the task at hand. The remaining voltage, if available, is dropped across the lamp. 6, 12, 24 volt?
Hi,

Yes, and i have actually done this in the past using a 40 watt 120vac bulb if i remember right. It was to drive a 12v clutch though not a motor. The compressor clutch needed 12vdc (dont remember the amps now) but i did not have a 12v power supply on hand at the time and it needed to be dedicated to the clutch so it could be operated at any time. I ended up using a decent current rated bridge rectifier with a 40 watt bulb in series. The bulb had to drop more than 100v but it wasnt enough to light it up all the way so it was a little dim when the clutch was energized. Was kind of funny to see working :)
 
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