Micro SMPS
Really micro SMPS
Schematic same as on first page
My version use:
Transistors: 13003,no heatsinks
Bias Resistors: 680k
Divider capacitors: 47nF 250VDC (I plan to use 100nF)
Feedback resistor: 100R 0,5W
Bulk cap: 33uF 400V
Output cap: 470uF 25V
Input is rectified with only one diode,and 4R7 1W is used as softstart and fuse
Core:E19 from PC PSU,not rewounded,Primary used as primary and 5Vstandby secondary is used for feedback.It outputs about 10V when rectified.Other posibilities are 17 and 27V (depend where you tie output rectifier)
Rectifier is classic diode bridge with 4 fast diodes.
No output storage coil because core is gapped.
Ideal for AUX power supplies,LED power supply,Power SMPS supply for oscilator and drivers,amplifiers,etc.
On other prototype I use pins of secodary that give me about 17V,and then use 7812 stabiliser.Output current drawed from this secondary (without 7812) is about 4A for 1 minute,I use 12V 45W light bulb,and they shine very bright,like to blow up
On 10V secondary it can shine continually without any problem.
Scope shows output voltage at GND and 5V pin.
See pictures: