Power Supply Adapter

This is the design diagram of +15V / 1A regulated power supply using uA723. Circuit operation: The supply receives +20VDC from the rectifier / filter section (diode bridge). This is applied to pins 11 and 12 of the IC uA723, as well as to the collector of the 2N3055 series-pass transistor. The output voltage is simpled through R1 and R1, providing about 7V with respect to ground at pin 4. The reference terminal at pin 6 is tied directly to pin 5, the noninverting input of the error amplifier. For fine tuning output voltage, a potensiometer can be installed between R1 and R2. A 100 pF capacitor to pin 4 furnishes gain compesation for the amplifier .

This is the scheme design of -15V / 1A Regulated DC Power Supply . It used uA723 precision voltage regulator and TIP105 PNP Epitaxial Silicon Darlington transistor. The supply receives -20V from the rectifier/filted which is fed to the collector of the Darlington PNP pass transistor, a TIP105. The base drive to the TIP105 is supplied through resistor R5. The base of the TIP105 is driven from Vz terminal at pin 9, which is the anode of a 6.2V zener diode that connects to the emitter of the uA723 output control transistor.

This is the schematic diagram of voltage regulator circuit with pass transostor. The regulator is based regulator IC of LM317T. The LM317T output current can be raised by utilizing an additional power transistor (on circuit, it is 2N2955) to share a portion of the total current. The amount of current sharing is established with a resistor placed in series with the LM317 input and a resistor placed in series with the emitter of the pass transistor. In the above scheme design , the pass transistor will start conducting when the LM317 current reaches about 1 ampere, due to the voltage drop across the 0.7 ohm resistor. Current limiting happens at about 2 amperes for the LM317 which will drop about 1.4 volts across the 0.7 ohm resistor and make a 700 millivolt drop across the 0.3 ohm emitter resistor. Thus the total current is limited to about 2+ (.7/.3) = 4.3 amperes.

This is the high current dc power supply circuit with 5V output. The high current regulator utilizes an extra winding or a separate transformer to deliver power for the LM317 regulator so that the pass transistors can run closer to saturation and increase performance. For excellent performance the voltage at the collectors of the two parallel 2N3055 pass transistors ought to be near to the output voltage. The LM317 needs a couple extra volts on the input side, plus the emitter/base drop of the 3055s, plus whatever is lost across the (0.1 ohm) equalizing resistors (1volt at 10A), so a separate transformer and rectifier/filter circuit is utilized which is several volts higher than the output voltage.

This is the variable DC power supply circuit. This power supply has regulated output, can be adjusted from 3 to 25 volts and the current output is limited to 2 amps as shown, however it may possibly be improved up to 3 amps or more by applying a smaller current sense resistor (0.3 ohm). Voltage regulation is controlled by 1/2 of a 1558 or 1458 op-amp. The 1458 may be substituted in the circuit, but it is suggested the supply voltage to pin 8 be limited to 30 VDC, which can be achieved by adding a 6.2 volt zener or 5.1 K resistor in series with pin 8. The 2N3055 and 2N3053 transistors need to be attached on proper heatsinks and the current sense resistor must be rated at 3 watts minimum.

The 5V regulated power supply for TTL and 74LS series integrated circuits, has to be really precise and tolerant of voltage transients. These IC's are effortlessly damaged by short voltage spikes. A fuse will blow when its electric current rating is exceeded, but demands several hundred milliseconds to respond. This circuit will react in several microseconds, triggered when the output voltage exceeds the limit of the zener diode. This circuit uses the crowbar method, where a thyristor is employed and short circuits the supply, causing the fuse to blow. This will take position in a few microseconds or less, and so provides considerably higher protection than an ordinary fuse. If the output voltage exceed 5.6Volt, then the zener diode will conduct, switching on the thyristor (all in some microseconds), the output voltage is therefore reduced to 0 volts and sensitive logic IC's will probably be saved. The fuse will nonetheless take just a few hundred milliseconds to blow ...

This is a converter circuit which will convert 5VDC input to become 12VDC output. The circuit is based LT1070 which also will boost the current output. About LT1070: The LT ® 1070/LT1071 are monolithic high power switching regulators. They can be operated in all standard switching configurations including buck, boost, flyback, forward,inverting and “Cuk”. A high current, high efficiency switch is included on the die along with all oscillator, control and protection circuitry. Boost Converter circuit reference, download: LT1070 datasheet

The following diagram is the cheap Low-Dropout linear regulator circuit. This linear post regulator circuit provides 12 V at 3 A. It applies TL431 reference U1 which, without additional amplification, drives TMOS MTP3055A gate Q1 series pass regulator. Bias voltage is applied through R1 to Q1's gate, which is protected against overvoltage by diode CR1. Frequency compensation for closed-loop stability is provided by C1. Circuit Characteristics: Dropout voltage: 0.6 V Line regulation: ±5 mV Load regulation: 10 mV Output ripple: 10 mV pk-pk

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.

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

Parts list: TR = 2 x 15 volt (30volt total) 6+- amps D1...D4 = four MR750 (MR7510) diodes (MR750 = 6 Ampere diode) or 2 x 4 1N5401 (1N5408) diodes. F1 = 1 Amp F2 = 10 amp R1 = 2k2 2,5 Watt R2 = 240 ohm R3,R4 = 0.1 ohm 10 watt R7 = 6k8 ohm R8 = 10k ohm R9 = 47 0.5 watt R10 = 8k2 C1,C7,C9 = 47nF C11 = 22nF C2 = 4700uF/50v - 6800uF/50v C3,C5 = 10uF/50v C4,C6 = 100nF C8 = 330uF/50v C10 = 1uF/16v D5 = 1N4148, 1N4448, 1N4151 D6 = 1N4001 D10 = 1N5401 D11 = LED D7, D8, D9 = 1N4001 IC1 = LM317 T1, T2 = 2N3055 P1 = 5k P2 = 47 Ohm or 220 Ohm 1 watt P3 = 10k trimmer This is definitely an simple to create power supply which has reliable, clear and regulator 0 to 28 Volt 6/8 Ampere output voltage. By using two 2N3055 transistor, you'll get two times the amount of electric current. Although the 7815 power regulator is going to kick in on brief circuit, overload and thermal overheating, ...

The output voltage of this power supply circuit can be adjusted from 6 volt to 12 volt. The output voltage is regulated by Q1. Parts List: R1 = 470 ohm, 5% R2 = 1K, 5% P1 = 10K ohm Potentiometer C1 = 1000uF/25V T1 = 115[220]/8VAC transformer. Center Tap not needed. Q1 = 2N1613, NTE128, or substitute. (TO-39 case) On coolrib! BR1 = 40V, 4A. (Check max current of your mini-drill and add 2A) Notes: C1 filters the noise and spikes off the AC. If you find the circuit output too noisy add another electrolytic capacitor over the output terminals. Value can be between 10 and 100uF/25V. 10K-potentiometer used to adjust the output voltage. The transformer input voltage refer to your home power source. You may change the bridge diode with four rectifier diodes.

Here the simple 5V regulated power supply circuit which featured overvolatage protection. The circuit work: This circuit uses the crowbar method, where a thyristor is employed and short circuits the supply, causing the fuse to blow. This will take place in a few microseconds or less, and so offers much greater protection than an ordinary fuse. If the output voltage exceed 5.6Volt, then the zener diode will conduct, switching on the thyristor (all in a few microseconds), the output voltage is therefore reduced to 0 volts and sensitive logic IC's will be saved. The fuse will still take a few hundred milliseconds to blow but this is not important now because the supply to the circuit is already at zero volts and no damage can be done. The dc input to the regulator needs to be a few volts higher than the regulator voltage. Read more circuit explanation at http://www.zen22142.zen.co.uk/Circuits/Power/overvolt.htm

This is a negative adjustable power supply. The power supply is regulated based on LM337T regulator IC. The LM337T is a regulator for negative voltage. This power supply output current is 1.5A max. Schematic diagram: Power Supply Input: Component part list: R1 = 330 R2 = 1K VR1 = 10K 10-turn trimpot C1 = 2200uF/50V C2,4 = 100nF ceramic C3,4 = 10uF/63V D1-6 = 1N5403 REG IC = LM337T Heatsink This circuit is available in kit module at electronickits.com, you may buy the this power supply kit there. Here the manual of the kits which containing the schematic diagram, part list and the explanation of the power supply circuit.

Below is a positive regulated adjustable power supply based on LM317T regulator IC. The LM317T is a regulator for positive voltage. This power supply output current is 1.5A max. Schematic diagram: Power Supply Input: Component part list: R1 = 330 R2 = 1K VR1 = 10K 10-turn trimpot C1 = 2200uF/50V C2,4 = 100nF ceramic C3,4 = 10uF/63V D1-6 = 1N5403 REG IC = LM317T Heatsink This circuit is available in kit module at electronickits.com. Here the manual of the kits which containing the schematic diagram, part list and the explanation of the power supply circuit.

Here's a circuit diagram of the power supply and battery charger. There are two parts in this circuit, ie the battery charger with a fixed output voltage, which is 5VDC. Another part is the regulated power supply that can be regulated output voltage between 2-9 volts. source: http://www.electronics-lab.com

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.