I need 12V 2A power supply for DC motor. Can someone suggest me schematic? I found few schematics on web but I want suggestion of professionals here. I don't want to burn my house :)

Thanks in advance

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    \$\begingroup\$ Yeah, let's burn the entire neighborhood. You take a transformer 50W and bridge rectifier, that's it. \$\endgroup\$ – Marko Buršič Jan 20 '16 at 20:42
  • \$\begingroup\$ :) I know it will work with pulsating voltage (output of bridge rectifier) but I want to make an effort to get stable voltage :) \$\endgroup\$ – hari Jan 20 '16 at 20:50
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    \$\begingroup\$ For powering the DC motor you don't need a stable voltage, even a capacitor is not needed, because the inductivity of the motor will make the current smooth. Everythying you will add extra of graetz bridge is waste of money and additonal heat loss. \$\endgroup\$ – Marko Buršič Jan 20 '16 at 20:57
  • \$\begingroup\$ Ok. For bridge rectifier, are 1n4007 diodes appropriate? \$\endgroup\$ – hari Jan 20 '16 at 21:00
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    \$\begingroup\$ Of course, but I prefer bricks because it is easier to mount and you don't need a PCB and soldering, supposed that you have crimp tool. google.si/… \$\endgroup\$ – Marko Buršič Jan 20 '16 at 21:09

You could get a 50HZ halogen lamp transformer that has a 12Vac output and is rated at 3 AMPs .These transformers have internal thermal protection so you have a good safe design basis.So you wont burn anything down .You should also fuse the primary and the secondary.Next place a bridge rectifier and a large electrolytic cap to make DC for your motor .Using PWM to run the motor is a good idea to get the voltage dead right .

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  • \$\begingroup\$ Why would you need a large electrolytic cap? \$\endgroup\$ – Marko Buršič Jan 20 '16 at 21:26
  • \$\begingroup\$ The motor may not be happy on pulsating DC.With no cap the expected ripple is 48% which could be too high .10% or less would be better. \$\endgroup\$ – Autistic Jan 20 '16 at 21:39
  • \$\begingroup\$ Motor doesn't need a capacitor, rather a choke. The PWM electronic part needs capacitor, without it using only the bridge rectifier the caps aren't needed. If somehow torque ripple is a problem, then a choke (not a cap!) is needed. Also keep in mind that output of PWM goes to the motor directly, without cap, so there are very large ripples in PWM signal. \$\endgroup\$ – Marko Buršič Jan 21 '16 at 9:32
  • \$\begingroup\$ Chokes are great on DC motors.They should have significant inductive reactance at 100Hz where most of the ripple is .In fact a choke if done properly is better than a electrolytic cap for other reasons but the choke is big and harder to find. \$\endgroup\$ – Autistic Jan 21 '16 at 10:08

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