LM78XX Positive Regulators Universal PCB for PSU

The 78XX family is ideally suited for this job, and with this little PCB you can easily build small Power Supplies for virtually every application.

The circuit is very simple:

The Alternating current is applied to X1 and rectifies by B1.

It charges a large Capacitor C1 to power the regulator.

The output voltage depends on the Regulator you use, e.g. 7805, 7812,7815…

Dimensionierung:

C1:4700u, with sufficient voltage Rating!

C2:0.33u

C3:0.1u

Download this schematic diagram.

For download layout on PCB, pleace click here.

Datasheet semiconductor download. (PDF Format)

1. LM78XX

400Watt Audio Power Amplifier with MOSFET BUZ902DP

Download this schematic diagram.




Datasheet semiconductor component. (PDF Format)

1. BC556
2. 2SB716A
3. 2SD756A
4. BUZ902DP
5. BUZ907DP
6. IN4148

If you like in the sound system or sound this circuit will should like you , This amplifier has two completely separate mono amplifiers with each channel has its own power supply to the order of zero channel crosstalk, a common phenomenon in amplifiers have the same food.

To view the full performance of each supply transformer should be evaluated at 40VAC – 0 – 40VAC at 640VA.

Unlike many models of capacitors is a reservoir to supply the peak currents, I prefer the power transformer in a much faster transient. BUZ902DP Although the specifications are rather modest,

if they can hear you now to experience a large reserve of power available and never any reason to worry that something to do than drive a large number of amplifiers aloud. You do not hear nothing but the truth without distortion at all levels, and I can assure you that this amplifier is required to provide the best features coupled.

LM317T Voltage Regulator with Pass Transistor

The LM317T output current can be increased by using an additional power transistor to share a portion of the total current. The amount of current sharing is established with a resistor placed in series with the 317 input and a resistor placed in series with the emitter of the pass transistor.




Download this schematic.



Download list datasheet semiconductor parts. (PDF Format)

1. 2N2955
2. LM317A
3. IN4002

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Variable Voltage and Current Power Supply

Download this schematic.




Download list datasheet semiconductor parts. (PDF Format)

1. 2N3055
2. LM1458

Another method of using opamps to regulate a power supply is shown below. The power transformer requires an additional winding to supply the op-amps with a bipolar voltage (+/- 8 volts), and the negative voltage is also used to generate a reference voltage below ground so that the output voltage can be adjusted all the way down to 0. Current limiting is accomplished by sensing the voltage drop across a small resistor placed in series with the negative supply line. As the current increases, the voltage at the wiper of the 500 ohm pot rises until it becomes equal or slightly more positive than the voltage at the (+) input of the opamp. The opamp output then moves negative and reduces the voltage at the base of the 2N3053 transistor which in turn reduces the current to the 2N3055 pass transistor so that the current stays at a constant level even if the supply is shorted. Current limiting range is about 0 - 3 amps with components shown. The TIP32 and 2N3055 pass transistors should be mounted on suitable heat sinks and the 0.2 ohm current sensing resistor should be rated at 2 watts or more. The heat produced by the pass transistor will be the product of the difference in voltage between the input and output, and the load current. So, for example if the input voltage (at the collector of the pass transistor) is 25 and the output is adjusted for 6 volts and the load is drawing 1 amp, the heat dissipated by the pass transistor would be (25-6) * 1 = 19 watts. In the circuit below, the switch could be set to the 18 volt position to reduce the heat generated to about 12 watts.


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0-30V Stabilized Variable Power Supply with Current Control

This is high quality stabilized power supply circuit diagram. You will able to adjust the output voltage from 0 volt up to 30 volt DC. You also able to adjust the current output value from 0.002 A to 3 A.

Detail explanation include the PCB layout, visit this page

Current Expanded Regulated Power Supply

Actually, this is ordinary regulated power supply, but the current expander using a transistor make this power supply become powerful.

Based on the datasheet, the stabilizer IC’s can deliver up to 1A output current. For example 78xx series regulators are available in different voltage ratings, but in any case the current should not exceed 1A.

The transistor Q1 (2N 29055) used here has 5A current capacity. The resistor R1 is used to keep the current through regulator IC below 300mA. When the current through R1 increases the base current of Q1 (2N 29055) also increases & the load required load current flows through this transistor. By this way a current greater than the capacity of the regulator IC can be delivered to the load. The C1 is used to filter the ripples off the rectifier output.

Download this schematic diagram.

Notes:

1. Assemble the circuit on good quality PCB.
2. T1 can be a 230V primary,15V/1A secondary, step down transformer.
3. If 1 A bridge is not available, make one using four 1N 4007 diodes.
4. The series regulator IC should be selected according to the desired output voltage.

• IC 7805 for 05V
• IC 7806 for 06V
• IC 7809 for 09V
• IC 7812 for 12V

Semiconductor datasheet download. (PDF Format)

1. LM78XX
2. 2N2955