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Showing posts from June, 2011

Electronic Power Controller Circuit

This is an electric power controller which implemented the bidirectional triode thyristor(TRIAC). This circuit can manage the electrical power using the a single variable resistor.

This circuit is applied for the dimmer which adjusts the light from the bulb. This circuit adjusts the quantity of the electrical current which flows via the load together with the bidirectional triode thyristor and controls the electric power. It truly is only the alternating voltage that may be controlled with this circuit and it is impossible to perform the control in the DC voltage.

Simply because it controls the passing time in the alternating current by the bidirectional triode thyristor, the electrical current which flows via the load is not the clean sine wave type. Due to the fact it's, there is limitation in the equipment which may be controlled with this circuit. The bidirectional triode thyristor is usually called by the trade name TRIAC.

The equipment which can be controlled
The equipment whic…

Voltage Double Circuit with timer IC 555

This is a voltage double circuit which build using well-known timer IC 555. The circuit is very simple, and is easily to build. Construction is not crucial.

Here the schematic diagram:



Rectifier diodes should be ultrafast (UF4004 or similar), or you can use 1N4148 signal diodes. Losses will be slightly higher if you use signal diodes, or lower if you wanted to go to the trouble of using Schottky diodes - the latter are not warranted in such a simple circuit (IMO). The zener diode is to protect the circuit against transient overvoltage, and is optional.

Voltage Double Circuit with timer IC 555
source: http://sound.westhost.com/project95.htm

Current Output Doubler after 78xx Regulator

This is about how to increase the current output limit after voltage regulating process using regulator 78xx series. As we know, current output after 78xx regulator is about 1 - 1.5A. With this circuit, you will be able to get higher current output from regulated power supply.


Components List:
R1, R2 = 4.7 K
C1, C2 = 4700 uF / 16V
C3 = 47,000 uF / 35V
D1,D2, D3 = 1N5401 ( 3 Amp Diodes )
D4 & D5 – Light Emitting Diodes (LED)**
IC1, IC2 – 78xx series regulator IC ( 7805 for 5V, 7812 for 12V etc.)

Visit this page for detailed instruction and explanation how to doubling the current output after regulate the voltage with IC regulator 78xx series.

Voltage Doubler Circuit: 12VDC to 18VDC or 24VDC

Here the schematic diagram voltage converter circuit: 12VDC to 18VDC or 24VDC:


This voltage doubler circuit will convert 12-V power supply to become a 24VDC and 18VDC. Use this circuit with almost any PNP or NPN power transistor.


Component Parts list:
U1: NE 555 timer.
C1 and C2: 50μF/25V
Q1: TIP 29, TIP120, 2N4922, TIP61, TIP110, or 2N4921.
Q2: TIP30, TIP125, 2N4919, TIP62, TIP115, or 2N4918.

3A Switching Regulator Circuit

Here the simple and cheap switching regulator circuit which capable to deliver 3A electric current.



Use the heatsink on the transistor to prevent damage due to overheating on its.

UPS Circuit for Cordless Telephone

This is the schematic diagram of UPS CIrcuit for Cordless Telephone:


When the AC mains is present, the very same is converted into DC and fed to the inverter. A component of the mains rectified output is being used to charge the battery. When the mains power fails, the DC supply to the inverter is from the battery and from this is obtained AC at the inverter output.

The circuit wired around IC CD4047 is an astable multivibrator operating at a frequency of 50 Hz. The Q and Q outputs of this multivibrator directly drive power MOSFETS IRF540. The configuration applied is push-pull type. The inverter output is filtered as well as the spikes are reduced working with MOV (metal oxide varistor). The inverter transformer chosen is an ordinary 9V-0-9V, 1.5A mains transformer readily offered inside the market. Two LEDS (D6 and D7) indicate the presence of mains/battery.

The mains supply (when present) is stepped down, rectified and filtered working with diodes D1 via D4 and capacitor C1. A compone…

Dual Polarity Power Supply +33V, 0 , -33V

The following diagram is the example of dual polarity power supply circuit which will give you (+33V) ; (0) and (-33V) DC voltage. This circuit is usually used for power amplifier circuit which require dual polarity power supply to work.



Components List:
R1 = 3K3 1/2W
C1 = 10nF/1000V
C2,C3 = 4700µF/50V
C4,C5 = 100nF/63V
D1 = 200V 8A Diode bridge
D2 = 5mm. Red LED
F1,F2 = 3.15A Fuses with sockets
T1 = 220V Primary, 25 + 25V Secondary, 2A minimum
PL1 = Male Mains plug
SW1 = SPST Mains switch

source: redcircuits.com

Unregulated Dual Polarity Power Supply

This is the schematic diagram of Unregulated Dual Polarity power supply.


Unlike 78xx and 79xx dual polarity regulated power sypply and LM317/LM337 dual polarity regulated power supply which have limited current output and voltage (have limited supply power), this unregulated power supply will give you more power.

This kind of circuit usually used for power amplifier which need high supply power, or as high current lead acid battery charger (single polarity only).

The component value is flexible refer to your needs. For example: if you need power supply for 100W amplifier, then the component value are:
Transformer: 3A minimum (center tap)
Diodes: 3A diode (1N5401, 1N5402, 1N5403 etc)Electrolytic capacitor: 4x minimum of 4700uF/50V (the higher is better - check the capacitor voltage, change it for higher voltage. example: use 63V capacitors for 45V power supply output.)