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The easy way to power your projects
Here is the circuit diagram of regulated power supply. It is a small power supply that provides a regulated voltage, adjustable between 1.5 and 35 volts at 1 ampere. This circuit is ready to use, you just need to add a suitable transformer. This circuit is thermal overload protected because the current limiter and thermal overload protection are included in the IC.
Picture of the circuit:
Circuit diagram:
Transformer selection chart:
Parts:IC = LM317P1 = 4.7KR1 = 120RC1 = 100nF - 63VC2 = 1uF - 35VC3 = 10uF - 35VC4 = 2200uF - 35VD1-D4 = 1N4007
Features:- Just add a suitable transformer (see table)
- Great to power your projects and save money on batteries
- Suitable as an adjustable power supply for experiments
- Control DC motors, low voltage light bulbs, …
Specifications :- Preset any voltage between 1.5 and 35V
- Very low ripple (80dB rejection)
- Short-circuit, thermal and overload protection
- Max input voltage : 28VAC or 40VDC
- Max dissipation : 15W (with heatsink)
- Dimensions : 52x52mm (2.1” x 2.1”)
Technical Specifications- Input Voltage = 40Vdc max Transformer
- Output Voltage = 1.5V to 35Vdc
- Output Current = 1.5 Amps max.
- Power Dissipation = 15W max (cooled)
Note:- It has not to be cooled if used for small powers. 28 Volt AC max is allowed for the input voltage.
Low cost solution for charging of both NiCd and NiMh batteries
Here is the circuit diagram of a low cost universal charger for NiCD - NiMH batteries. This circuit is Ideal for car use. It has ability to transform a mains adapter in to a charger . This one can be used to charge cellular phone, toys, portables, video batteries, MP3 players, ... and has selectable charge current. An LED is located in circuit to indicate charging. Can be built on a general purpose PCB or a veroboard. I hope you really like it.
Picture of the circuit:
Circuit diagram:
Parts:R1 = 120R-0...5WR2 = See DiagramC1 = 220uF-35VD1 = 1N4007D2 = 3mm. LEDQ1 = BD135J1 = DC Input Socket
Specifications:- Ideal for in car use.
- LED charge indication.
- Selectable charge current.
- Charges Ni Cd or NiMH batteries.
- Transforms a mains adapter into a charger.
- Charge cellular phone, toys, portables, video batteries …
Features:- LED function indication.
- Power supply polarity protected.
- Supply current: same as charge current.
- Supply voltage: from 6.5VDC to 21VDC (depending on used battery)
- Charge current (±20%): 50mA, 100mA, 200mA, 300mA, 400mA. (selectable)
Determining the supply voltage:This table indicates the minimum and maximum voltages to supply the charger. See supply voltage selection chart below.Example:To charge a 6V battery a minimum supply voltage of 12V is needed, the maximum voltage is then 15V.Voltage selection:
Determining the charge current:Before building the circuit, you must determinate how much current will be used to charge the battery or battery pack. It is advisable to charge the battery with a current that is 10 times smaller then the battery capacity, and to charge it for about 15 hours. If you double the charge current , then you can charge the battery in half the time. Charge current selection chart is located in diagram.Example:A battery pack of 6V / 1000mAh can be charged with 100mA during 15 hours. If you want to charge faster, then a charge current of 200mA can be used for about 7 hours.
Caution:The higher charge current, the more critical the charge time must be checked. When faster charging is used, it is advisable to discharge the battery completely before charging. Using a charge current of 1/10 of the capacity will expand the lifetime of the battery. The charge time can easily be doubled without damaging the battery.Note:- Mount the transistor together with the heatsink on the PCB, bend the leads as necessary. Take care that the metal back of the transistor touches the heatsink. Check that the leads of the transistor do not touch the heatsink.
Portable and small unit, Can be built on a veroboard
Firstly, I'd like to stress that the intended use of this circuit is only one of many possible applications. Apart from the obvious usage as a headphone amplifier, the circuit can be used for a range of applications where a wide bandwidth low power amplifier is needed. The circuit is based on an opamp, with its output current boosted by a pair of transistors.
The bias diodes should be 1N914 or similar - power diodes are not recommended, as their forward voltage is too low. This may result in distortion around the crossover region, where one transistor turns off and the other on. Credit for this circuit goes to SiliconChip
Picture of the circuit:
Parts layout:
PCB layout:
Circuit diagram:
Parts List:
Resistors
P1 = 50K
R1 = 56K
R2 = 22K
R3 = 330K
R4 = 10K
R5 = 10K
R6 = 33R
R7 = 33R
R8 = 68R
Capacitors
C1 = 0.27uF
C2 = 10uF-35V
C3 = 5pF
C4 = 100nF-63V
C5 = 100nF-63V
Semiconductors
D1 = 1N914
D2 = 1N914
Q1 = BC338
Q2 = BC328
IC1 = TL072
Misc.
J1 = Audio Input Socket
J2 = Stereo Headphone Socket
Performance of Prototype
Output level == 90mR (max) into 8W headphones
Input sensitivity == 0.83V RMS for full power
Frequency response == 0.5dB down at 30Hz and 20kHz
Signal-to-noise ratio == -95dB unweighted (20Hz to 20kHz) with respect to 500mV input signal
Separation between channels = = -50dB between 20Hz and 10kHz
Small but powerful multipurpose amplifier
This small amplifier is constructed around the TDA2003 IC, capable of delivering 4Wrms at 4ohms. The TDA 2003 has improved performance with the same pin configuration as the TDA 2002. The additional features of TDA 2002, very low number of external components, ease of assembly, space and cost saving, are maintained. The device provides a high output current capability (up to 3.5A) very low harmonic and cross-over distortion. Completely safe operation is guaranteed due to protection against DC and AC short circuit between all pins and ground, thermal over-range, load dump voltage surge up to 40V and fortuitous open ground. A conventional direct current can be connected as supply.
Circuit's picture:
Circuit diagram:
Parts:R1 = 470RR2 = 47RR3 = 100RR4 = 1RC1 = 1822pFC2 = 100nF-63VC3 = 100nF-63vC4 = 10uF-25VC5 = 470uF-25VC6 = 1000uF-35vC7 = 1000uF-35VIC1 = TDA2003
Specifications:- Music power output: 7W / 4ohm
- RMS output: 3.5W / 4ohm or 2W / 8ohm
- Total harmonic distortion: 0.05% (1W / 1kHz)
- Frequency response: 20Hz to 20kHz (-3dB)
- Signal/noise ratio: 86dB (A weighted)
- Input sensitivity: 40mV / 150Kohm
- Overload and short-circuit protected
- Supply voltage: 15V DC (8 to 18V DC possible) / 0.5A
- Dimensions: 2.2 x 1.4"
Small in size! Big in use
Here is a simple and powerful LED circuit that can be operated directly from the AC 100 volt to AC 230 Volts mains supply. The circuit can be used as mains power locator or night lamp etc.. The resistor R1,R2 and capacitor C1 provides necessary current limiting. The circuit is sufficiently immune against voltage spikes and surges.
Circuit's pictures:
Circuit diagram:
Parts:D1 = 1N4007D2 = 1N4007D3 = 1N4007D4 = 1N4007R2 = 1M-1/2WR1 = 470R-1/2WC1 = 220nF-275vACD5 = 5mm. Blue LED
Features:- Small in size!
- Blue LED operated on mains voltage
- Suited for mains indicator or other pilot lamps
- For safety guidance, stairs, corridors…
- Special X2 safety capacitor
- 100Vac to 240Vac 50Hz or 60Hz Operated
- Dimensions: 28x18mm / 1.10 x 0.71"
Note:- Only for use inside a cabinet
- The capacitor C1 can be polyester type.
- Also white LED can be used in this circuit.
- Assemble the circuit on a general purpose PCB.
Safety and Hazard WARNINGS:This circuit operates on a lethal power voltage. Mount the circuit in a protective cabinet prio to applying AC Power. Do not modify the circuit - Wait 10 minutes before touching the circuit after disconnecting the AC Power. This circuit is not intended for children.
