Power Supply Adapter

This simple circuit makes it posible to monitor the charging process to a higher level. If you need more information then check out the LM3914 Datasheet . Final adjustsments are simple and the only thing needed is a digital voltmeter for the necessary accuracy. Connect an input voltage of 12.65 volt between the positive and negative poles and adjust the 10K trimmer potentiometer until Led 10 lights up. Lower the voltage and in sequence all other Led's will light up. Check that Led 1 lights up at approximately 11.89 volts. At 12.65 volt and higher the battery is fully charged, and at 11.89 is considered 'empty'. The green Led's indicate that the battery capacity is more than 50%, the yellow Led's indicate a capacity of 30% - 50% and the red Led's less that 30%. This circuit, with the components shown, uses less than 10mA. Of course you can adapt this circuit to your own needs by making small modifications. The circuits above is set for 'DOT' mode, meanin...

Do you need assembled power supply ..? If your answer is yes, then this assembled digital power supply should be great to buy. Product specification: Two level of control for both current and voltage outputs: coarse and fine for ease of use Adjustable outputs: 0-30V and 0-5A Input voltage: 110V AC and 220V AC switchable Ripple noise: CV You can BUY THIS POWER SUPPLY at Amazon.com

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...

Here the Uninterruptible Power Supply (UPS) circuit with PIC17C43 microcontroller. Your UPS will be automatically controlled by the microcontroller. UPS systems are traditionally designed using analog components . Today these systems can integrate a microcontroller with AC sine wave generation, offering the many benefits. The PIC17C43 microcontroller handles all the control of the UPS system. The PIC17C43 is unique because it provides a high performance and low cost solution not found in other microcontrollers. Download the document of Uninterrupted Power Supply

This power supply will give you fixed regulated output at 5V, 6V, 9V and 12V, while the 18V output is unregulated. You could add some regulated IC like LM7815 or 7818 if you need higher output voltage. This circuit provide an audio indicator that will act like an alarm if any circuit short contact.

This is the power supply circuit for general purpose usage. The supply can be used for supply output voltages from 1 to 35V. The line transformer should be selected to give about 1.4 times the desired output voltage from the positif side of filted capacitor C1 to ground. Potensiometer R2 sets the output voltage to the desired value by adjusting the reference input. Rsc is the current limit set resistor. For example, if the maximum current output is to be 1A, Rsc=0.65/1.0 = 0.65 Ohm. The 1KOhm resistor,R5, is a light-loaded resistor designed to improve the no-load stability of the supply.

Battery charger for general purpose usage. The charger's output voltage is adjustable and regulated, and has an adjustable constant-current charging circuit that makes it easy to use with most NiCad batteries. The charger can charge a single cell or a number of series-connected cells up to a maximum of 18V. Power transistors Q1 and Q2 are connected as series regulators to control the battery charger 's output voltage and charge-current rate. An LM-317 adjustable voltage regulator supplies the drive signal to the bases of power transistor Q1 and Q2. Potensiometer R9 sets the output-voltage level. A current sampling resistor, R8 (a 0.1 ohm/5W unit), is connected between the negative output lead and circuit ground. For each amp of charging current that flows through R8, a 100mV output is developed across it. The voltage developed across R8 is fed to one input of comparator U3. The other input of the comparator is connected to variable resistor R10. As the charging voltage across...

This is an adjustable power supply circuit , also known as variable power supply. . You may use this circuit for general purpose usage. Here the schematic diagram : Component list: R1 = 560R 1/4W C1 = 100nF R2 = 1,2 K 1/4W C2 = 2200uF 35-40V R3 = 3,9 K 1/4W C3 = 100 pF R4 = 15K 1/4W C4 = 100uF/ 35V R5 = 0,15R 5W D = B40 C3300/2200, 3A rectifier bridge P1 = 10K potesiometer TR1 = BD 135 ...

This is variable power supply for multi purpose usage and very useful to supply your electronic tools or your projects. Voltage range will be 0.7 - 24V and the urrent limiting range is 50mA - 2A. Components: P1____________500R Linear Potentiometer P2_____________10K Log. Potentiometer R1,R2__________2K2 1/2W Resistors R3____________330R 1/4W Resistor R4____________150R 1/4W Resistor R5______________1R 5W Resistor C1__________3300µF 35V Electrolytic Capacitor (see Notes) C2_____________1µF 63V Polyester Capacitor D1,D2_______1N5402 200V 3A Diodes D3____________5mm. Red LED Q1___________BC182 50V 100mA NPN Transistor Q2___________BD139 80V 1.5A NPN Transistor Q3___________BC212 50V 100mA PNP Transistor Q4 _________2N3055 60V 15A NPN Transistor T1____________220V Primary, 36V Center-tapped Secondary 50VA Mains transformer (see Notes) PL1___________Male Mains plug SW1___________SPST Mains switch Notes: P1 sets the maximum output current you want t...

Here the regulated power supply circuit that will give you current output up to 20A depends the number of power transistor used in the circuit . You can build the box like this: here te schematic diagram : for further instruction, visit this page

This is a regulated dual polarity power supply (download schematic and pcb layout HERE ): The output of this circuit will be positif output(+), normal/ground output(0) and negative output(-). IC LM317 is used to regulate the positive output and LM337 is used to regulate the negative output. You should use TAP transformer for this circuit and heatsink for the IC. Please visit this page for complete explanation Another dual polarity power supply circuit, visit here

This inexpensive variable power supply circuit with L200. The output current is up to 2A and the output voltage depends to the output voltage from transformer. VR 47R used for current adjustment and the VR10K used for output voltage adjustment.

This is regulated variable power supply circuit based on Transistor LM338. Short circuit protection added in this circuit .

This is a simple but reliable power supply circuit based one of the oldest integrated voltage regulators of them all - the LM723. Please visit this page for complete explanation.

Component parts list: P1____________500R Linear Potentiometer P2_____________10K Log. Potentiometer R1,R2___________2K2 1/2W Resistors R3____________330R 1/4W Resistor R4____________150R 1/4W Resistor R5______________1R 5W Resistor C1___________3300µF 35V Electrolytic Capacitor (see Notes) C2______________1µF 63V Polyester Capacitor D1,D2________1N5402 200V 3A Diodes D3_____________5mm. Red LED Q1____________BC182 50V 100mA NPN Transistor Q2____________BD139 80V 1.5A NPN Transistor Q3____________BC212 50V 100mA PNP Transistor Q4 __________2N3055 60V 15A NPN Transistor T1_____________220V Primary, 36V Center-tapped Secondary 50VA Mains transformer PL1____________Male Mains plug SW1____________SPST Mains switch Notes: P1 sets the maximum output current you want to be delivered by the power supply at a given output voltage. P2 sets the output voltage and must be a logarithmic taper type, in order to obtain a more linear scale voltage indication. Yo...

Here a variable power supply circuit which the output voltage can be adjusted. The stabilizer IC may be changed with different value as needed, example 7815 for 15v maximum voltage. Component Parts List: T1 Transformer 10:1 Secondary 24V @ 2A BR1 Bridge Rectifier 50V PIV 2A rating C1 4700u (35V) C2 0.001u C3 2200u (35V) C4 0.001u C5 4.7u (25) C6 0.01u R1 10k potentiometer L1 see text U1 7805 N.B. This may be changed for different output voltages e.g. 7812 for higher output voltage ZD1 15V zener @ 1.3W The specific inductance of the ferrite (core)is important. A core should be chosen to work within the specific frequency as stated by the manufacturer. L1 is a powder core and has 32 turns of 0.75mm wire. The transformer has a 240V primary and has a secondary rated 24V at 2A. The bridge rectifier contains 4 diodes, their current rating needs to be high with respect to the transformers output current; if not the current may damage the diodes. C1 is the mainfiltering capacitor, the suppl...

Here the +50V / 3A Stabilized and Regulated Power Supply. schematic diagram: component parts list: R1= 10Kohm R2= 1 ohm 5W R3= 3.9 ohms 1W R4= 6.8Kohm 1W R5= 390 ohms 1W R6= 100Kohm 0.5W R7= 1.2Kohm 1W R8= 1.8Kohm 0.5W R9= 3.3Kohm 0.5W RV1= 470 ohms pot. Q3= BC303 or BC461 D1....4= Bridge 15A D5= LED RED 5mm C1-2-4= 4700uF 100V C3-5= 100nF 250V MKT D6-7= 10V 1W Zener D8-9-10= IN4007 Q1= 2N3055 on heatsink T1= 230Vac / 55V 3A Q2= BD162 or BD243 or BD543 Note: It 's a circuit that can give in his exit + 40V until + 60V 3A, with simultaneous stabilization. The materials that use is very simple and will not exist difficulties in the manufacture, is enough you are careful certain points: For output voltages smaller of + 50V until + 40V, the Q1 is hot enough, so that it needs one big heatsink. For output voltages bigger of + 50V up to + 70V, the stabilization is not satisfactory. Conclusion: ideal output voltage is + 45V until + 60V. In the circuit potensiometer RV...

This is 0-15 volt / 1 Ampere power supply circuit diagram . This is very simple and easy to built, the output is stabilized and regulated. Maximum output 15V and 1 Ampere, u can use this circuit for common electronic devices like radio , cd player, mini amplifier or just for your experimental circuits. Components list: R1= 56ohm 2W R2= 330ohm Lin. pot. C1= 2200uF 35V C2= 100uF 35V C3= 10uF 25V C4= 220uF 25V C5= 100nF 100V Q1= 2N3055 GR1= 4 X 1N4007 D1= 18V 1.5W zener T1=220V@18V 1.5A

Very high current regulated power supply . This circuit require a transformer which have output 24v / 35A. It should be an expensive circuit :( Notes: The input transformer is likely to be the most expensive part of the entire project. As an alternative, a couple of 12 Volt car batteries could be used. The input voltage to the regulator must be at least several volts higher than the output voltage (12V) so that the regulator can maintain its output. If a transformer is used, then the rectifier diodes must be capable of passing a very high peak forward current, typically 100amps or more. The 7812 IC will only pass 1 amp or less of the output current, the remainder being supplied by the outboard pass transistors. As the circuit is designed to handle loads of up to 30 amps, then six TIP2955 are wired in parallel to meet this demand. The dissipation in each power transistor is one sixth of the total load, but adequate heat sinking is still required. Maximum load current will generate maxi...

13.8 Volt 10 A regulated power supply . You need 10 Ampere transformer for this circuit . Complete explanation about this circuit , please visit this page .

This PSU has been especially designed for current-hungry ham radio transceivers. It delivers safely around 20Amps at 13.8V. For lower currents, a separate current limiting output, capable of 15ma up to a total of 20A has been added. The power transformer should be capable to deliver at least 25A at 17.5 to 20V. The lower the voltage, the lower power dissipation. The rectified current will be “ironed” by the C1, whose capacity should not be less than 40.000uF, (a golden rule of around 2000uF/A), but we recommend 50.000uF. This capacity can be built up by several smaller capacitors in parallel. The base of this design is a simple 12V regulator (7812). The output voltage can be brought to desired value (here 13.8V) by two external resistors (R5 and R6) using this formula: U= 12(1+R5/R6) The low currents (here 15mA) will keep the 7812 in its regular function. As soon as the current rises over 15ma, the voltage drop on R4 will “open” the Q3, actually handling the high output current. Thi...

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. Notes: Assemble the circuit on good quality PCB. T1 can be a 230V primary,15V/1A secondary, step down transformer. If 1 A bridge is not available, make one using four 1N 4007 diodes. The s...

Here is 9V Regulated Power Supply schematic diagram : You can use this power supply for your electronics project which only require electric current about 500mA. This is cheap circuit which will give you stabilized output voltage. If you want to change the output voltage, you should change the IC type. For example, you need 5V output, then change the IC from 7098 with 7805 dan change the output of transformer from 16V AC become 9VAC or 12V AC.

This simpl e circuit will protect the costly equipment from high as well as low voltages and the voltage surges (when power resumes). It also gives a melodious tune when mains power resumes. When mains voltage is normal, the DC voltage at the cathode of zener diode D4 is less then 5.6V. As a result transistor T1 is in ‘off’ state. The DC voltage at the cathode of zener diode D5 is greater than 5.6V and as a result transistor T2 is in ‘on’ state. Consequently, relay RL1 gets energised, which is indicated by lighting up of green LED . Under high mains voltage condition, transistor T1 switches to ‘on’ state because the voltage at cathode of zener diode D4 becomes greater than 5.6V. Consequently, transistor T2 switches to ‘off’ state, making the relay to de-energise Under low mains voltage condition, transistor T1 switches to ‘off’ state and as a result transistor T2 also switches to ‘off’ state, making the relay to de-energise. Read more explanation here

This circuit is not really simple, but will save your money :). This over/under voltage cut-out will save your costly electrical and electronic appliances from the adverse effects of very high and very low mains voltages. The circuit features auto reset and utilises easily available components . It makes use of the comparators available inside 555 timer ICs. Supply is tapped from different points of the power supply circuit for relay and control circuit operation to achieve reliability. The circuit utilises comparator 2 for control while comparator 1 output (connected to reset pin R) is kept low by shorting pins 5 and 6 of 555 IC. The positive input pin of comparator 2 is at 1/3rd of Vcc voltage. Read more explanation here

This is a simple low-cost 12 Volt 50W off-line switching power supply , which can be used for home projects or to learn operation of flyback converters. It can work over a universal AC line input range 90-264 VAC and provides a 12VDC output at more then 4A load. Line and load regulation is better then 0.5%. The unit has overcurrent, overtemperature and overvoltage protections as well as passive inrush current limiting. Output ripple are approximately 0.2 V. If you need to get lower ripple, you may put an additional output LC filter. Complete explanation, visit this site

This page come from my.integritynet.com.au , will show you about how to make a variable regulated power supply . This type of regulation is ideal for having a simple variable bench power supply . Actually I think this is quite important because one of the first projects a hobbyist should undertake is the construction of a bench supply. While a dedicated supply is quite handy e.g. 12V, it's much handier to have a variable supply on hand. There have been many times I have had to "smoke test" a project. This means I have started out at the minimum voltage on my supply (about 3V), seen nothing untoward happening and then slowly winding up the voltage to say 15V (this would only be where the project design called for 15V). By the way, this is the recommended way to test a project after having double checked parts placement against circuit drawings and parts placement guide (if any). Always start out at minimum voltage and look for signs of distress among components (usuall...

Let's look at the very common LM340-X series or the equivalent 78XX series. Firstly they come in a variety of voltage ranges from 5, 12 and 15V for LM340-XX and 78XX. They also come in a variety of current ratings and package sizes. Common packages are TO-92, TO-5, TO-220 and TO-3. The first two, TO-92 and TO-5 are generally unavailable to the hobbyist because suppliers like to keep reduced stock lines and so tend only to stock the TO-220 and TO-3 types. In fact you can pay more for a TO-92 type (rated at 100 ma) than you would for a TO-220 type (rated at 1.5A) When you have a requirement for a project of say 12V, or even 5V if it's a digital project, then these are the types you use. LM340-5, LM340-12 or 7805 or 7812 are the types. There are of course negative voltage regulators with the numbers LM320-XX or 79XX which are substantially the same as those discussed here excepting they are negative. We will not consider them further. Assume your project calls for a basic fixe...

To regulate small amounts of current the cheapest approach is to use a zener diode. Higher currents can be obtained from higher power zeners but I prefer to use dedicated I.C.'s in these cases. In one instance you can use a zener diode in conjunction with a pass transistor to extend the range of the zener regulator. As with our previous design example in Part - 1 we had a small unregulated bench supply of 500 ma for our projects . Now we have decided that it should become a well regulated, well filtered supply giving us 13V dc. By using a series pass transistor we are extending the useful range of the zener diode as well as reducing Vo ripple. This is called "electronic filtering". There is one large handicap with this circuit though. Under over-current conditions Q1 will most likely be destroyed long before F1 blows. Of course I have very cynical (practical?) friends who will tell you that if you buy up Q1 types at 5c each then in fact they are cheaper than most fuses ...

The ac from the transformer secondary is rectified by a bridge rectifier D1 to D4 which may also be a block rectifier such as WO4 or even four individual diodes such as 1N4004 types. (see later re rectifier ratings). The principal advantage of a bridge rectifier is you do not need a centre tap on the secondary of the transformer. A further but significant advantage is that the ripple frequency at the output is twice the line frequency (i.e. 50 Hz or 60 Hz) and makes filtering somewhat easier. As a design example consider we wanted a small unregulated bench supply for our projects. Here we will go for a voltage of about 12 - 13V at a maximum output current (I L ) of 500ma (0.5A). Maximum ripple will be 2.5% and load regulation is 5%. Now the rms secondary voltage (primary is whatever is consistent with your area) for our power transformer T1 must be our desired output Vo PLUS the voltage drops across D2 and D4 ( 2 * 0.7V) divided by 1.414. This means that Vsec = [13V + 1.4V] / ...

If you are not experienced in dealing with it, then leave this project alone. Although Mains equipment can itself consume a lot of current , the circuits we build to control it, usually only require a few milliamps. Yet the low voltage power supply is frequently the largest part of the construction and a sizeable portion of the cost . This circuit will supply up to about 20ma at 12 volts. It uses capacitive reactance instead of resistance; and it doesn't generate very much heat.The circuit draws about 30ma AC. Always use a fuse and/or a fusible resistor to be on the safe side. The values given are only a guide. There should be more than enough power available for timers, light operated switches, temperature controllers etc, provided that you use an optical isolator as your circuit's output device. (E.g. MOC 3010/3020) If a relay is unavoidable, use one with a mains voltage coil and switch the coil using the optical isolator. C1 should be of the 'suppressor type'; mad...

This is transformerless power supply schematic diagram . Please take a note that this circuit running ONLY for input voltage 110V AC. I use this power supply for applications that doesn't use too mucho power. It can provide power to circuit that uses less than 100mA without any problem. The disadvantage of this circuit is the danger of an electrical shock, so it cannot be used if the circuit is in contact with the user. The voltage supplied by this is determined by the zener diode. The version of the transformerless power supply that uses a bridge rectifier provides more current than the first one because it rectifies both phases of the AC voltage.

This is a very basic AC to DC rectifier power supply . The transformer is chosen according to the desired load. For example, if the load requires 12V at 1amp current, then a 12V, 1 amp rated transformer would do. However, when designing power supplies or most electronic circuits , you should always plan for a worst case scenario. With this in mind, for a load current of 1 amp a wise choice would be a transformer with a secondary current rating of 1.5 amp or even 2 amps. Allowing for a load of 50% higher than the needed value is a good rule of thumb. The primary winding is always matched to the value of the local electricity supply. Notes: An approximate formula for determining the amount of ripple on an unregulated supply is: where I load is the DC current measured through the load in amps and C is the value of the capacitor in uF.The diagram below shows an example with a load current of 0.1 amp and a smoothing capacitor value of 1000uF. The calculated value of ripple is (0.1 *...