parallel cellphone chargers

[ric.dealban]

hi. i have a dc motor i bought from amazon japan with brand "option no.1" but i forgot to order the power supply in tandem with it which is a 2-4v constant 4a. i improvised and paralleled the input and output of two 5v 2a cellphone charger hoping i could get a higher output current. my parallel charger has a working output voltage of 5.2v but i have no means of measuring the output current. so i connected it to the dc motor but it doesn't work. i measured the input voltage while it is connected to the motor and the reading is zero. what could have gone wrong.. thank you in advance

 

[kellys_eye]

Test the power packs individually - they should be capable of driving the motor under no-load conditions. You'd only need the 4A for heavy loads on the motor.

Some phone power packs might detect the motor as a short-circuit and not output anything. Try adding a large electrolytic capacitor across the output of the power packs to see if it helps.

 

[ric.dealban]

Test the power packs individually - they should be capable of driving the motor under no-load conditions. You'd only need the 4A for heavy loads on the motor.

Some phone power packs might detect the motor as a short-circuit and not output anything. Try adding a large electrolytic capacitor across the output of the power packs to see if it helps.

I am really not familiar of the motor load. But Inalao used this supplies:

12V 2A - motor is running fast but the torque is low
3.5V 3.5A -motor is running slow and torque is also low
12V 4.5A - the motor is retrying

I’m so confused on what supply should i use to make it run in high speed and high torque. I cant find the data sheet of the motor.

See attached photo

 

[kellys_eye]

12V 4.5A - the motor is retrying

This sounds like the stall current i.e. the maximum current.

Best power supply for motors is a linear PSU i.e. derived from an old style laminated transformer unit and NOT the Switched Mode versions that are identified by being 'light weight' (in size and performance).

There are still such PSUs around easily identified by them being 'brick-like' in weight so perhaps you could try to find one? If you can't find one of the correct voltage then consider getting some form of regulation or even a speed controller fitted to the output.