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Showing posts from May, 2011

5V DC / 10A Offline Switching Power Supply

Offline switching power supply which resulting 5VDC/10A output from 110/220V AC home power electric. See the parts list, there should be different MOSFET type for 110V anf 220V volatage input.

Below the diagram:




And here the parts list:


The schematic shows a 50-W power supply with a 5-V 10-A output. It is a flyback converter operating inside the continuous mode. The circuit has functionality of a main side and secondary side controller will full-protection from fault conditions such as overcurrent. When the fault condition has been removed, the power supply will go into the soft-start cycle just before recommencing normal operation.

Positive Voltage Regulator Circuit with PNP Boost

The IC8211 presents the voltage reference and regulator amplifier, although Q1 will probably be the series pass transistor. R1 defines the output current of the IC8211, although C1 and C2 present loop stability and as well act to suppress feedthrough of input transients to the output supply. R2 and R3 define the output voltage as follows:



Furthermore, the values of R2 and R3 are preferred to create a bit volume of standing current in Q1, which provides additional stability margin on the circuit.Where accurate setting of the output voltage is needed, either R2 or R3 could possibly be designed adjustable. If R2 is designed become adjustable,then the output voltage will vary linearly with the shaft angle; nevertheless, if the potentiometer wiper was to open the circuit, the output voltage would rise. Normally, for that reason, it is far more beneficial to provide R3 adjustable, due to the fact this can give fail-safe operation.

Low Forward-Drop Power Supply Circuit

Check out the signal output... this power supply will cut off the negative amplitudo and pass the positive AC signal.

A TMOS power FET , Q1 , and LM393 comparator supply a higher performance rectifier circuit. When VA exceeds VB, U1's output turns into higher and Q1 conducts. Conversely, when VB exceeds VA, the comparator output gets low and Q1 does not conduct.

The forward drop is determined by Q1's on resistance and latest I. The MTH40N05 has an on resistance of 0.028 Ohm; for I = 10 A, the forward drop is much less than 0.3 V. Typically, the very best Schottky diodes usually do not even start conducting below several hundred mV.

9V Stabilized Power Supply Circuit with LM723

Here the 9V Stabilized power supply circuit. Built based IC 723 and featured with amp booster using 2N3055. The 2N3055 must be mounted on a coolrib/heatsink.

Schematic Diagram:



Components List:

R1 = 0.56 Ohm, 1 Watt, wire-wound type, 5%
R2 = 750 Ohm, 5%
R3 = 2K7 (2700 ohm)
P1 = potentiometer, 1K, Linear
C1 = 2200uF, 35V
C2 = 470pF
T1 = 115/10 VAC transformer. Center Tap (ct) not needed.
IC1 = uA723, LM723, or equivalent.
Q1 = 2N3055, NTE130, or substitute. (TO-3 case) Mount on a coolrib!
BR1 = 80V-5A (or better)

Circuit Notes:
C1 filters the noise and spikes off the AC. Adjust the circuit for 9V or 12V output voltage, or whatever voltage level your pc mini drill is using, with the P1 potentiometer.Q1 can also be a MJ2955 in a TO-3 case.

Design by Tony van Roon
Source: http://www.sentex.ca/~mec1995/circ/9vstable.htm