Transformer less power supply 12v 100mA

 

As we all know for DC power supply we always use SMPS or TRANSFORMER but as we are making small device we cannot use both because it will increase the size of our device and not just size also cost. low voltage dc source like 3.3 volts, 5 volts, 12 volts is necessary for the field of electronics or for small electronic circuits, normally we use batteries to power them but it is cost effective and also wastes of time and energy, That’s why we are going to make the transformerless power supply.

Here is the list of all components to make our circuit board 

  •  684J/400V NON-POLARISED CAPACITOR
  • 2W10 BRIDGE RECTIFIER DIODE
  • ZERO PCB
  • 270 OHM / 2WATTS RESISTANCE
  • 16V/47-470uf CAPACITOR
  • 12V/2WATTS ZENER DIODE

 

Now first we need Zero PCB board there we install 684J/400V capacitor, This capacitor is X-RATED non-polo rise capacitor which is specially designed for AC CURRENT.

Below is the chart for output current and output voltage (without the Load), of different values of X-rated capacitors, you can choose acording to your need

Capacitor Code

Capacitor value

Voltage

Current

104J

                  0.1 uF

   4 v

    10 mA

334J

                 0.33 uF

  10 v

    20 mA

474J

                 0.47 uF

  12 v

    30 mA

684J

                 0.68 uF

  18 v

   100 mA

105J

                   1 uF

  24 v

    50 mA

225J

                  2.2 uF

  24 v

    100 mA

 

Now installed and solder 2W/270ohm resistance the PCB (2 watts will be better for heat handling or dissipation )

Here I am using  2W10 it is full wave bridge rectifier diode, which is the combination of four diodes internally, you can use any bridge rectifier diode on this place or you can easily make bridge rectifier by using IN4007 diodes, both will work almost similar. Now we will solder first PN pin of the bridge rectifier to the 684J/400V capacitor and second PN pin of the bridge rectifier to the 270-ohm resistance.

 

BE CAREFUL WHILE DOING SOLDERING 

Now take 1Watt/12Volts zener diode, The black color on zener diode indicates cathode side. Now connect zener diode Cathode pin to bridge rectifier diode positive output pin (PP PIN) and Anode pin of zener diode to a negative output of bridge rectifier diode (NN PIN)

 

Now we will use a 16volts/47uf electrolytic capacitor, capacitor positive on zener diode cathode and negative to an anode of zener diode

Finally, our circuit board is complete

The circuit output current is very less it can be touch with bare hands, now we will test the voltage output on a multimeter, The multimeter is showing a reading of 13 volts but when we will apply load on the circuit board it will be approx 11.5 or 12 volts. In case if you want to increase or decrease the output volts change the value of zener diode.

 

Here you can see the circuit diagram of the whole project, this circuit output current is approx 100 mah and 12 volts, it is capable  to run small circuits or some LEDs,

As I have mentioned above that the circuit output current is easy to touch but don’t touch the circuit board it will be harmful to you. MAKE IT AT YOUR OWN RISK IT CAN BE DANGEROUS TO WORK WITH ALTERNATING CURRENT (AC) WITHOUT PRECAUTION AND EXPERIENCE.  

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