Power Supply Adapter

This is a very simple battery charger for your car battery. The most expensive part of this circuit is a 5 A transformer. A car battery has very high value of electric current , so it's require battery charger with high electric current output.

This is an power supply failure alarm which will give you an alert when the power supply getting off or fail to supply. It employs an electrolytic capacitor to store adequate charge, to feed power to the alarm circuit which sounds an alarm for a reasonable duration when the supply fails. To calibrate the circuit , first connect the power supply (5 to 15V) then vary the potentiometer VR1 until the buzzer goes from on to off. Whenever the supply fails, resistor R2 pulls the base of transistor low and saturates it, turning the buzzer ON. Take a note that this circuit will be work only on power supply with output voltage 5 - 15 Volt DC. Source: http://www.electronic-circuits-diagrams.com/alarmsimages/alarmsckt2.shtml

Below general power supply circuit has 2 static output type, stabled output at 5VDC and adjustabled output or variable output. Here the circuit diagram : The circuit is based on the regulator IC 7805 . It has only 3 connections (input, output and ground) and it provides a fixed output. The last two digits of the part number specify the output voltage, eg. 05, 06, 08, 10, 12, 15, 18, or 24. The 7800 series provides up to 1 amp load current and has on-chip circuitry to shut down the regulator (rather than blowing out) if any attempt is made to operate it outside its safe operating area. (If this happens to you, let the chip cool down and attach the heatsink.). Visit this page more detail about general power supply.

Featured with short circuit protection and overload protection, this variable regulated power supply will is very nice for your electronic equipments. The voltage output range will be 3-30 volt DC with 3A current. Download the manual of this circuit include the schematic diagram and part list from HERE Source: circuitdiagram.net

This is the schematic diagram of bench power supply . This bench powersupply will be great to support your activity if you are an electronics hobbyst: Take a note that based on the diagram, this circuit require 120V AC to 17V AC Center Tapped Transformer. If your country use 220V AC home electric source, you MUST change the Transformer 220-240V AC to 18V AC Center Tapped Transformer. More information of this bench power supply, visit this page

This is a regulated power supply circuit with dual polarity output. There are 3 output that are (+) voltage, (0) Grounding, and (-) voltage. The current output max about 0.3-0.5 A. IC 78xx is used as positive voltage regulator while IC 79xx is used as negative voltage regulator. You need center tapped (CT) transformer 0.5-1A for this circuit . Use transformer voltage output refer to your need. For example, if you need 12v output, you should connect J1 to 15v transformer output, J2 connected to 0v and J3 connected to another 15V.

This is a unregulated dc power supply circuit which have ability to handle high current load. Component parts: R1_________ 680 Ohm 1/4 Watt Resistor C1_________ 20,000 - 50,000uF 20-40 Volt Capacitor C2, C3_____ 100uF/50 Volt Capacitor C4_________ 0.1uF 50 Volt Capacitor C5_________ 0.01uF 50 Volt Capacitor D1_________ Zener Diode Q1_________ 2N3055 Or Other T1_________ Transformer BR1________ Bridge Rectifier S1_________ SPST 250 VAC 10 A Switch MISC_______ Case, Line Cord, Heatsink For Q1, Binding Posts For Output NOTES: D1 should be rated at about one volt higher than then desired output of the supply. A half watt diode will do. Q1 can be a transistor similar to the 2N3055. T1 should be about 5 volts higher than the desired output of the supply, and rated for about one amp more of current. The voltage overhead is required by the regulator section. The extra current is to keep the transformer from over heating. The choice of BR1 will depend on the voltage and current of your transf...