Showing posts with label to. Show all posts
Showing posts with label to. Show all posts
Friday, October 24, 2014
Build a Voltage Regulator 12v to 24v using 7812
How to build a voltage regulator 12v to 24v using 7812. What many people do not know is it possible for a voltage regulator IC to provide an output voltage higher than its actual value. One method to achieve this is by connecting the "common" terminal to the middle point of a potential divider, but the problem with this method is that the regulators IC has a small quiescent current (~ 10 mA) flowing out the common terminal to ground.
The circuit presented here avoids the problems of using the IC regulator to raise the voltage via the transistor Q1 to generate a low impedance to the common terminal video controller during the transfer of the voltage divider from a resistor divider network relatively high. The value of R3 is not critical, but should be low enough to accept the higher quiescent current without causing problems for T1.
Voltage Regulator 12v to 24v Circuit Diagram
The circuit presented here avoids the problems of using the IC regulator to raise the voltage via the transistor Q1 to generate a low impedance to the common terminal video controller during the transfer of the voltage divider from a resistor divider network relatively high. The value of R3 is not critical, but should be low enough to accept the higher quiescent current without causing problems for T1.
Voltage Regulator 12v to 24v Circuit Diagram
Simple Voltage to Frequency Converter Circuits Diagram
This Simple Voltage to Frequency Converter Circuits Diagram has a 1 Hz-to-30 MHz output, 150-dB dynamic range, for a 0 to 5 V input. It maintains 0.08% linearity over its entire 71/3 decade range with a full-scale drift of about 20 ppm/°C. To get the additional bandwidth, the fast )FET buffer drives the Schottky TTL Schmitt trigger.
Simple Voltage to Frequency Converter Circuits Diagram
The Schottky diode prevents the Schmitt trigger from ever seeing negative voltage at its input. The Schmitt`s input voltage hysteresis provides the limits which the oscillator runs between. The 30-MHz, full-scale output is much faster than the LTC1043 can accept, so the digital divider stages are used to reduce the feedback frequency signal by a factor of 20. The remaining Schmitt sections furnish complementary outputs.
Monday, October 20, 2014
Build a Period To Voltage Converter Circuit Diagram
this is the simple Period To Voltage Converter Circuit Diagram. The input signal drives ICD. Because ICD`s positive input (V+) is slightly offset to + 0.1 V, its steady state output will be around +13 V. This voltage is sent to ICC through D2, setting ICC`s output to +13 V. Therefore, point D is cut off by Dl, and CI is charged by the current source.
Assuming the initial voltage on CI is zero, the maximum voltage (^Cinax) is given by: When the input goes from low to high, a narrow positive pulse is generated at point A. This pulse becomes -13 V at point B, which cuts off D2. ICC`s V+ voltage becomes zero.
Period To Voltage Converter Circuit Diagram
The charge on CI will be absorbed by ICC on in a short time. The time constant of C2 and R5 determines the discharge period— about 10 /is. ICB is a buffer whose gain is equal to (R& + R9)~Rg = lM5. ICD`s average voltage will be (1362f 1.545) + 2 = 1052/. RIO and C3 smooth the sawtooth waveform to a dc output.
Now 0 to 40V Lab Power Supply
A very lab adjustable power supply that can provide an output voltage between 0 and 60 volts can be designed using this circuit diagram . This lab power supply can be designed with LM723 chip or for higher output voltages, with L146 .Output current is also adjustable, but once established, is always effective. Table 1 shows the values to be modified to have three different versions of the maximum output voltage (30, 40 and 60 V).
Electrical diagram below shows the alternative 40 V / 0.8 using L146 chip because it can stabilize higher output voltage, much better than the LM723. Normally, 2 V is the minimum voltage stabilized that even an integrated circuit can provide. Resistive network R3, R4 and R5, R6 "kill" this restriction so that output can be set to 0 V with potentiometer P2.
Depending on the output requirements, will be decided on the type and the semiconductor capacitors to be used. Output current must be limited so as to keep power dissipation of 40 W. T3 under maximum output current for 40 V version is 0.8 A. It can connect two parallel 2N3055 transistors (with emitter resistors) to double the current output, but in this case requires a 2 A transformer
Saturday, October 11, 2014
How to Repairing Switching Power Supply
Up to date power supply are renowned as "switching controller power supply." In most swapping supply, the 110 volt AC input is first rectified by two diodes and filtered by a pair of capacitors. This conceives two high- voltage causes; one positive and the other negative. A pair of transistors is then utilized to switch these high voltage supply over the primary winding of a transformer.
This switching activity is very fast. A usual switching pace is around 40,000 circuits per second or 40KHz. An integrated circuit is commonly utilised to control the transistors. This IC not only controls the pace at which the transistors are swapped, but furthermore controls the amount of time that each transistor is energized. The yield voltage of the power supply is very resolute by the "on" time of the transistors. If the transistors are hold on for a longer time span of time, the output voltage of the provide will rise, while shorter times smaller the yield voltage. This is renowned as "pulse-width modulation."
Power Supply
Thursday, September 18, 2014
Inductorless 3 to 5 Volts Converter
By configuring a comparator and a transistor to control the oscillator in a charge pump circuit, you enable the pump to generate a regulated output of in principle any desired value. Charge pump ICs can either invert or double an input voltage (for example, 3 V to –3 V or 3 V to 6 V). The charge pump itself does not regulate the output voltage and one running off 3 V is not normally capable of generating intermediate output voltage levels like 5 V. However, by adding a comparator and a reference device, you can create arbitrary output levels like 5 V and regulate them as well.
Circuit diagram :
Inductorless 3-to-5 Volts Converter Circuit Diagram
Charge pump IC1 (a MAX660) has an internal oscillator whose 45 kHz operation transfers charge from C1 to C2, causing the regulated output to rise.
When the feedback voltage (pin 3 of IC2) exceeds 1.18 V, the output of comparator IC2 (a MAX921) goes high, turning off the oscillator via T1. The comparator hysteresis (easily added on IC2) is zero here simply because no hysteresis is required in the control loop. The oscillator when enabled generates two cycles, which is sufficient to drive VOUT slightly above the desired level. Next, the feedback turns the oscillator off again.
The resulting output ripple will depend mainly on the input voltage and the output load current. Output ripple may be reduced at the expense of circuit efficiency by adding a small resistor (say, 1 ?) in series with C1. You’ll find that ripple also depends on the value and ESR associated with C1 - smaller values of C1 transfer less charge to C2, producing smaller jumps in V OUT.
Author: D. Prabakaran
Sunday, December 22, 2013
Combine stereo input to one output
Here , I will give a circuit of schemes that are used to combine 2 pieces input or stereo to 1 input mono. Why 2 inputs in to one because, if we need a stereo amplifier we want to become a stronger by combining the two input into one input, so that a higher power output. Actually without any circuit above we can combine stereo amplifier into mono, but the sound output less than the maximum , need for this additional combiner circuit.
R1______150K
R2______920R
R3______150K
R4______920R
R5______920R
U1______NE5532
For balance _: R1 / R2=R3 / R4
For balance _: R1 = R3
Gain ______: R5 / R1 = R5 / R3
Simple Doubler Voltage 12 to 24Volt DC
This take place simple Doubler Voltage circuit, from voltage 12VDC to be 24VDC. By benefit Timer IC highly prevalent the come to NE555 and other equipment a modest again. It can make happen current contract in relation to 50mA fitting pro the circuit, with the intention of use low current the insignificant-sized.
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| Simple Doubler Voltage 12 to 24 VDC Schematic Diagram |
The belief facility of the circuit be present, at what time use Volt input 12VDC give with the circuit long for converge Filter current smoothly with increasingly. The capacitors C5 give with IC1, The resistor R1,R2 and , capacitors C1, Which build the circuit ideal astable multi vibrator open place wave generator, by the side of the frequency with reference to 2KHz befall shown the way pin 3 of IC1. By take capacitors C3,C4 diode D1 and D2. Which build come to pass boost up voltage x 2,which self-control enhance the level Volt out be the sincere current about 24VDC or else 2 time of the level Volt input.
Sunday, December 15, 2013
Inverter Circuit 12VDC to 220V 50Hz 500W
This is circuit Inverter 12VDC to 220V 50Hz 500W.
It easy to make and Low cost. Friends favorite circuit about the the inverter, because like working outdoors, or to backup storage to use when necessary. Most of this is circuit low power, which is not suitable for practical applications. My friends said that he would be about 500 Watt.
It is a good size. Use with television receivers and light bulbs as well. When looking for circuit. I get headaches. If you are a beginner or I can not buy expensive good quality circuits. Requires only one transistor. Or if you have free time. I want to build old circuit is alive again. This circuit will accommodate all your needs. It is a simple circuit.
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| Inverter 12VDC to 220V 50Hz 500W |
The same principle, I take battery voltage 12V to produce a oscillator about 100 Hz and pass to a two frequency divider circuit is only 50HZ. And drive a 10 ampere transformer with 10 x 2N3055 transistor in parallel. By a single transistor has 2A, when I use 10 transistors or 5 pairs of drive high current output. The complexity of circuit, but the principle is not it, and it is the number of transistors on a basic, easy to buy. You may be modified 100 watt power inverter To the size of transistors and transformers as well.
Source: leksound project
Saturday, November 30, 2013
Smart Tracker track anything from your child to shoes
The EPE Minder consists of two type- approved transmitter units and a receiver. If either transmitter becomes separated from the receiver, a buzzer in the latter part will sound.
The receiver is fitted with a switch to allow the use of only one transmitter if required.
MIND HOW YOU GO
This system was originally designed as a two-channel child alarm (to protect either a single child or two children at the same time) but many other applications spring to mind. For example, one transmitter could be placed inside a briefcase and another in a coat pocket. If the user forgot to pick up either of these items and walked away, the buzzer would sound in the receiver. The receiver must be carried on the per- son in a way that would make it practically impossible to lose it. This could be done using a belt clip, for example. Note that it will not be possible to use this system if either the transmitter or receiver were placed inside metal containers or if there were substantial metallic “screening” objects between them.
OPERATING RANGE
The operating range may be adjusted according to the intended purpose. However, it does depend on conditions. Adjustment is carried out by means of “aerial link wires” on the circuit panels. With all these in place, the range of the prototype exceeds 12 metres in open air. It will also work throughout several rooms indoors if required. If the battery voltage in either transmit- ter or receiver falls below a certain value, or if a transmitter is switched off, a buzzer will sound. The specified batteries in the transmitters should provide several hun- dred hours of operation. Those in the receiver should provide around 100 hours.
PERSONAL CODE
The EPE Minder uses a system of digitally encoded low-power radio signals,
which pass from the transmitters to the receiver. The code is different for each transmitter so that the receiver is able to distinguish one from the other. Type-approved, pre-aligned transmitter and receiver modules that operate at 433MHz. are used. No traditional “radio” skills are needed and no licence is needed for their use in the UK.
TRANSMITTER CIRCUIT
The circuit diagram for a single trans- mitter unit is shown in Fig.1. Current is
supplied to the circuit from a 3V “coin” cell, B1, via on-off switch S2 and diode D1. The diode provides reverse-polarity protection. It is best to use the specified Schottky device which introduces a smaller forward voltage drop, and therefore less loss, than a conventional silicon diode (0·2V rather than 0·7V approximately). Capacitor C2 provides a small reserve of energy and pre- vents the supply voltage from fluctuating. This stabilises operation. A low power 7555 timer, IC1, is set up in a standard astable (pulse generator) con- figuration. While switched on, this produces a continuous train of on-off pulses at its output, pin 3.The choice of resistors R1, R2 and capacitor C1 provide one pulse per second for one of the transmitters (Unit A) and one pulse every 1·2 seconds for the other one (Unit B). In fact, the timings are slightly longer but it helps to consider them as above. Also, the on times are much longer than the off ones in each case. The purpose of this will be explained presently.
RECEIVER CIRCUIT
Receiver module, IC1, requires a supply of between 4·5V and 5·5V. The 6V nomi-
nal battery pack, B1, is brought within range by the forward drop of diode D5
(0·7V approx.) This diode also provides reverse-polarity protection. Capacitor C4 charges up and provides a small reserve of energy. This will be useful when the battery is nearing the end of its operating life. When the supply voltage falls below some 4V, the receiver stops working and the buzzer will sound. Below around 3V, the buzzer itself will not operate so it is important to check operation each time the units are used. Receiver IC1 should be of the a.m. (amplitude modulation) type as specified in the components list. As such, it will respond to the on-off pulses provided by the transmitter. The inexpensive super regenerative (rather than superhet) variety will be perfectly adequate. The low-power variants of these receivers have not been tested. Although for battery operation they would appear to be ideal, the standard type is more readily available.
The receiver may be considered as hav- ing separate r.f. (radio frequency) and a.f. (audio frequency) sections. These have individual supply inputs (pins 1, 10, 12 and 15 with some being duplicated). These are all connected together and decoupled using capacitor C1.
TESTING
Having completed the Receiver board, we can now commence testing all three
boards. It helps to minimise the Receiver “hold-off” time by adjusting preset VR1 fully anti-clockwise (as viewed from the left-hand side of the p.c.b.) and preset VR2 fully clockwise (as viewed from the right- hand side of the p.c.b.). Check that the Test link has been left unconnected to prevent IC4b signal from passing to transistor TR1’s base. Switch on Single Channel switch S3 so that Channel A is enabled. With On-Off switch S4 off, insert the batteries. Switch on. After a short delay, the buzzer WD1 should sound. Now place Transmitter A approximately
three metres away from the Receiver, insert the battery and switch on. The buzzer should begin to bleep every second. The same procedure is now repeated for Transmitter B. To do this, switch S3 off to disable Channel A and firmly twist together the ends of the Test link wires. It is not advisable to solder this connection unless the i.c.s are removed first. The buzzer should bleep at a slightly slower rate than for Transmitter A. It is unlikely that the time periods of the two transmitters will be the same (due to overlapping component tolerances).
However, if they are, one of them will need to be changed. Choose slightly higher values for resistors R1 and R2 to slow it down and vice versa. Remove the i.c.s before making any modifications.
HOLD-OFF TIME
When both transmitters have been test- ed, switch S3 on to enable both channels. presets VR1 and VR2 should now be adjusted to approximately mid-track posi- tion. This should provide a sufficient “hold off” time plus a small margin. The buzzer should now remain off and only sound when one of the transmitters is switched off or moved out of range. Leave them operating for several minutes. If the occasional spurious bleep is heard, increase the settings of VR1/VR2 to pre- vent this happening.
Read More..
The receiver is fitted with a switch to allow the use of only one transmitter if required.
MIND HOW YOU GO
This system was originally designed as a two-channel child alarm (to protect either a single child or two children at the same time) but many other applications spring to mind. For example, one transmitter could be placed inside a briefcase and another in a coat pocket. If the user forgot to pick up either of these items and walked away, the buzzer would sound in the receiver. The receiver must be carried on the per- son in a way that would make it practically impossible to lose it. This could be done using a belt clip, for example. Note that it will not be possible to use this system if either the transmitter or receiver were placed inside metal containers or if there were substantial metallic “screening” objects between them.
OPERATING RANGE
The operating range may be adjusted according to the intended purpose. However, it does depend on conditions. Adjustment is carried out by means of “aerial link wires” on the circuit panels. With all these in place, the range of the prototype exceeds 12 metres in open air. It will also work throughout several rooms indoors if required. If the battery voltage in either transmit- ter or receiver falls below a certain value, or if a transmitter is switched off, a buzzer will sound. The specified batteries in the transmitters should provide several hun- dred hours of operation. Those in the receiver should provide around 100 hours.
PERSONAL CODE
The EPE Minder uses a system of digitally encoded low-power radio signals,
which pass from the transmitters to the receiver. The code is different for each transmitter so that the receiver is able to distinguish one from the other. Type-approved, pre-aligned transmitter and receiver modules that operate at 433MHz. are used. No traditional “radio” skills are needed and no licence is needed for their use in the UK.
TRANSMITTER CIRCUIT
The circuit diagram for a single trans- mitter unit is shown in Fig.1. Current is
supplied to the circuit from a 3V “coin” cell, B1, via on-off switch S2 and diode D1. The diode provides reverse-polarity protection. It is best to use the specified Schottky device which introduces a smaller forward voltage drop, and therefore less loss, than a conventional silicon diode (0·2V rather than 0·7V approximately). Capacitor C2 provides a small reserve of energy and pre- vents the supply voltage from fluctuating. This stabilises operation. A low power 7555 timer, IC1, is set up in a standard astable (pulse generator) con- figuration. While switched on, this produces a continuous train of on-off pulses at its output, pin 3.The choice of resistors R1, R2 and capacitor C1 provide one pulse per second for one of the transmitters (Unit A) and one pulse every 1·2 seconds for the other one (Unit B). In fact, the timings are slightly longer but it helps to consider them as above. Also, the on times are much longer than the off ones in each case. The purpose of this will be explained presently.
RECEIVER CIRCUIT
Receiver module, IC1, requires a supply of between 4·5V and 5·5V. The 6V nomi-
nal battery pack, B1, is brought within range by the forward drop of diode D5
(0·7V approx.) This diode also provides reverse-polarity protection. Capacitor C4 charges up and provides a small reserve of energy. This will be useful when the battery is nearing the end of its operating life. When the supply voltage falls below some 4V, the receiver stops working and the buzzer will sound. Below around 3V, the buzzer itself will not operate so it is important to check operation each time the units are used. Receiver IC1 should be of the a.m. (amplitude modulation) type as specified in the components list. As such, it will respond to the on-off pulses provided by the transmitter. The inexpensive super regenerative (rather than superhet) variety will be perfectly adequate. The low-power variants of these receivers have not been tested. Although for battery operation they would appear to be ideal, the standard type is more readily available.
The receiver may be considered as hav- ing separate r.f. (radio frequency) and a.f. (audio frequency) sections. These have individual supply inputs (pins 1, 10, 12 and 15 with some being duplicated). These are all connected together and decoupled using capacitor C1.
TESTING
Having completed the Receiver board, we can now commence testing all three
boards. It helps to minimise the Receiver “hold-off” time by adjusting preset VR1 fully anti-clockwise (as viewed from the left-hand side of the p.c.b.) and preset VR2 fully clockwise (as viewed from the right- hand side of the p.c.b.). Check that the Test link has been left unconnected to prevent IC4b signal from passing to transistor TR1’s base. Switch on Single Channel switch S3 so that Channel A is enabled. With On-Off switch S4 off, insert the batteries. Switch on. After a short delay, the buzzer WD1 should sound. Now place Transmitter A approximately
three metres away from the Receiver, insert the battery and switch on. The buzzer should begin to bleep every second. The same procedure is now repeated for Transmitter B. To do this, switch S3 off to disable Channel A and firmly twist together the ends of the Test link wires. It is not advisable to solder this connection unless the i.c.s are removed first. The buzzer should bleep at a slightly slower rate than for Transmitter A. It is unlikely that the time periods of the two transmitters will be the same (due to overlapping component tolerances).
However, if they are, one of them will need to be changed. Choose slightly higher values for resistors R1 and R2 to slow it down and vice versa. Remove the i.c.s before making any modifications.
HOLD-OFF TIME
When both transmitters have been test- ed, switch S3 on to enable both channels. presets VR1 and VR2 should now be adjusted to approximately mid-track posi- tion. This should provide a sufficient “hold off” time plus a small margin. The buzzer should now remain off and only sound when one of the transmitters is switched off or moved out of range. Leave them operating for several minutes. If the occasional spurious bleep is heard, increase the settings of VR1/VR2 to pre- vent this happening.
Saturday, November 23, 2013
8 to 18 volts TDA2005 Power Amplifier
This time, there is a series of audio amplifer 20W as well, but using IC TDA 2005 as a series of his base amplifier. The series of 2x20 Watt Audio Power Amplifier using TDA2005 can you see in the picture below.
Technical Data:
Performance of TDA2005M: (for this circuit); At 4.14 V supply voltage: 2 x 20 watts (stereo) into 4 Ohms.
Distortion: Approx. 0.2% at 4 Watts into 4 ohm load.Frequency Range: Approx. 20 Hz to 22 KHz.
Input Sensitivity: Approx. maximum 150 mV rms. .
Power supply: + 8 to 18 volts, approx. 3.5 Amps maximum per channel.
source [link]
Thursday, November 21, 2013
Simple Circuit 12V to 120V DC DC Converter
Its a simple circuit of 12V DC to 120V DC converter. The circuit consists of two phases first phase of the investor base and then a rectifier and filter stage. IC1 NE555 is wired as an astable multivibrator operating at a frequency of 100 Hz and can be adjusted to the preset R1. IC1 output is coupled to the clock input of IC2 is a dual CMOS D flip-flop. IC2 divides the pulse train of 100 Hz IC1 2 50 Hz pulse trains that are 180 degrees out of the party and offered on the pin 1 and 2 of IC2.When pin 1 is high transistor Q1 conducts and current flows through the upper half of T1 primary winding. When pin 2 is the transistor Q2 conducts and high current flows through the lower half of the primary coil T1. As a result of a voltage of 120 V AC are induced in the secondary of T1. This voltage is rectified with bridge D1 to provide a 120V DC output. Capacitor C2 is the DC input filter, while C3, C4 are the output filters.
Notes.
- The circuit can be assembled on a vero board.
- Q1 and Q2 require heat sink.
- Output power of this dc dc converter is around 100 watts.
- IC1 and IC2 are to be mounted on holders.
- An optional 5A fuse can be added in series to the 12V supply line.
- T1 can be a 9-0-9V /250V/3A mains transformer.
- If 3A bridge is not available make one using 1N5408 diodes.
- Out of the two Flip-Flops inside CD4013 only one is used here.
- Output of IC1 must be set to 100Hz by adjusting preset R1
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