Showing posts with label 5. Show all posts
Showing posts with label 5. Show all posts
Wednesday, April 10, 2013
5 Volt Switching Regulator Power Supply
The switching regulator power supply used LM2575-5.0 on this schematic. You can make the stable voltage by using the 3 terminal regulator like LM317. However, because the output electric current and the inputted electric current are the same approximately, the difference between the input electric power (The input voltage x The input electric current) and the output power (The output voltage x The output current) is consumed as the heat with the regulator. Because it is, the efficiency isn�t good.
Data sheet for LM2575
SIMPLE SWITCHER 1A Step-Down Voltage Regulator
http://www.national.com/pf/LM/LM2575.htm
Monday, April 8, 2013
5 Watts FM RF Amplifier
This
fm rf amplifier uses 2SC1971 transistor to provide 5 watts of output.
Output matching is adjusted via the two 40pF trimmer capacitors
likewise also to the input. Note that the emitter of this transistor is
directly grounded on the heat sink and should have a good thermal
transfer. Driving power of 100 to 200mW can be applied in order to
provide 5watts of output. Use a dummy load to tune this amplifier and
remember that the transistor is biased in Class C, sufficient
filtering should be followed after the output to minimize all the
harmonics. Use ground plane construction technique in the PCB lay-out
for best result, the more the grounding the better. If you have hard
time finding the 10uH rf choke, try to wind 1/2 meter of 0.2mm enamel
wire over a 33K 1/2 watt resistor and solder the coil ends to the legs
of the resistor.
fm rf amplifier uses 2SC1971 transistor to provide 5 watts of output.
Output matching is adjusted via the two 40pF trimmer capacitors
likewise also to the input. Note that the emitter of this transistor is
directly grounded on the heat sink and should have a good thermal
transfer. Driving power of 100 to 200mW can be applied in order to
provide 5watts of output. Use a dummy load to tune this amplifier and
remember that the transistor is biased in Class C, sufficient
filtering should be followed after the output to minimize all the
harmonics. Use ground plane construction technique in the PCB lay-out
for best result, the more the grounding the better. If you have hard
time finding the 10uH rf choke, try to wind 1/2 meter of 0.2mm enamel
wire over a 33K 1/2 watt resistor and solder the coil ends to the legs
of the resistor.
Friday, March 22, 2013
5 Band Graphic Equaliser circuit with LA3600 and PCB
Graphic equalisers are a must in any good hi-fi systems! They enable you to shape the response of the system to the particular room, or in recordings to improve deficiencies of the equipment or the original recording. A good equalizer, used with skill can dramatically improve the quality of your listening pleasure.
This equalizer has five bands which cover all the audible frequencies, centred at 100, 320, 1,000, 3,500 and 10,000 Hz. The spacing between peak frequencies is two octaves which is quite adequate for most domestic applications. Frequency adjustment is 12dB/octave.
The circuit is for one channel and if you want to use it for STEREO you should build two, one for each channel of your system.
Technical Specifications – Characteristics
Working voltage: 6-15V DC
Frequency response: 20Hz-20KHz
Current: 60 ma
How it Works
This equaliser has five bands which cover all the audio frequencies, around 100, 320, 1,000, 3,500 and 10,000 Hz.
The circuit is for one channel and if you want to use it for STEREO you need two. The circuit consists of one LA3600 IC.
The circuit has been designed so that when the potentiometers are in the middle of their travel the signal is not affected at all. Turning a potentiometer in either direction will affect the corresponding frequency range accordingly. The maximum output voltage without distortion is 1 Vpp. The equaliser operates from a 12 VDC power supply which makes it suitable for use in home or car.
Construction
This work is not very difficult and if you stick to a few rules you should have no problems. The soldering iron that you use must be light and its power should not exceed the 25 Watts. The tip should be fine and must be kept clean at all times. For this purpose come very handy specially made sponges that are kept wet and from time to time you can wipe the hot tip on them to remove all the residues that tend to accumulate on it. The construction of the equaliser is very easy if you follow the diagrams and our advice carefully. The only really sensitive component are the IC. Start building the circuit by soldering the pins and the IC sockets in their places on the p.c. board. Solder then the resistors, the capacitors, making sure that the electrolytic are inserted the right way round before soldering them, and finally the potentiometers.
Depending on the size and the shape of the case you are going to use for the project you can either solder the potentiometers on the p.c. board directly or use short pieces of shielded audio cable to connect them with the rest of the circuit. When you have finished soldering the components on the board check everything for possible mistakes, clean the board with a solvent to remove all traces of soldering flux and insert the IC’s in their sockets. Make sure that you align them properly and that you do not bend their pins during insertion. Make then the following connections using shielded cable for the input and output and preferably twisted twin cable for the power supply.
- The supply (6-15 VDC recommend 12volt DC) must be connected at points 1 (+) and 2 (-) of the board.
- The input is at points 5 (signal) and 4 (earth).
- The output is at points 3 (signal) and 4 (earth).
If you turn the power on, and the potentiometers of the equaliser are in their middle position there shouldn’t be any notice able difference to the music if the equaliser is inserted or not in the signal path. However turning the potentiometers should produce a noticeable effect to the reproduction.
Parts
C1 = 2.2mF 22v
C2 = 47nF
C3 = 680nF
C4 = 15nF
C5 = 220nF
C6 = 4.7nF
C7 = 68nF
C8 = 1.2nF
C9 = 22nF
C10 = 470pF
C11 = 6.8nF
C12 = 1nF
C13 = 2.2mF
C14 = 100mF 22v
C15 = 100mF 22v
R1 = 4.7k
R2 = 10k
R3, 4, 5, 6, 7 = 100k Potentiometers
IC = LA3600 link
Thursday, March 21, 2013
1 5 35 Volt DC Regulated Power Supply
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 = LM317
P1 = 4.7K
R1 = 120R
C1 = 100nF - 63V
C2 = 1uF - 35V
C3 = 10uF - 35V
C4 = 2200uF - 35V
D1-D4 = 1N4007
Features:
Specifications :
Technical Specifications
Note:
Picture of the circuit:
1A Regulated Power Supply Circuit Schematic
Circuit diagram:
1A Regulated Power Supply Circuit Diagram
Transformer selection chart:
Transformer selection Guide-Table For Power Supply
Parts:
IC = LM317
P1 = 4.7K
R1 = 120R
C1 = 100nF - 63V
C2 = 1uF - 35V
C3 = 10uF - 35V
C4 = 2200uF - 35V
D1-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.
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