Showing posts with label circuit. Show all posts
Showing posts with label circuit. Show all posts
Best Battery Charger Circuit Diagram
Best it mean UJT battry charger circuit diagram. This UJT battry charger circuit diagram will not work unless the battery to be charged is connected with proper polarity. The battery voltage controls the charger and when the battery is fully charged, the charger will not supply current to the battery. The battery charging the current is obtained through the SCR when it is triggered into the conducting state by the UJT relaxation oscillator.
The oscillator is only activated when the battery voltage is low. V8281 of the UJT is derived from the voltage of the battery to be charged, and since Vp= Vn= V8281 ; the higher V828` the higher Vp. When Vp exceeds the breakdown voltage of the zener diode Zl, the UJT will cease to fire and the SCR will not conduct. This indicates that the battery has attained its desired charge as set by R2.
UJT battry charger circuit diagram
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Super High Power Portable TV and FM Jammer Circuit Diagram
This is the Super High Power Portable TV and FM Jammer Circuit Diagram. There are still neighbors that keep annoying you by having loud the TV or the radio? Well I have you the solution. In fact all neighborhood will face your jamming waves at their TVs and radios, so be careful.
This Jammer is the improved version of the old `TV and FM jammer schematic` with the difference of much higher power. Many of you where asking for a stronger and wider effect but to be as portable as can be. Looking at the schematic you can see that, only the parts are changing keeping the basic circuit intact. Have in mind that this version needs heat sink and antenna to keep the transistor alive.
Super High Power Portable TV and FM Jammer Circuit Diagram
The power source comes from three 9 volt batteries in series, so we use 27 volts at input, and we get a power full 2,5 Watts at output.
You are going to need 70cm to 2 meter simple wire antenna.
As for the transistor Q its the 2N3553. Its a RF Power Silicon NPN Transistor in a TO39 type package designed to be used in amplifiers and oscillator applications in military and industrial equipment.
Usually found as an output driver, or in predriver stages in VHF equipment, but because here we dont care about the modulation of the signal but just the power, thats why we use it as a first and final output driver.
The transistor is specified at 175MHz and 28V to give: Output Power: 2.5W, Minimum Gain: 10dB and Efficiency: 50%.
The parts are: R1=10k, R2=2,2K, R3=100 C1=47uF/50V, C2=2.2nF, C3=10pF, SW=switch, B=Battery 9V.
The coil L should be closely wound 5 turns (start tunning with the closely wound distance of turns and then play with it and the C4 capacitor, to find the desired frequency )of enameled copper wire 1.5mm and internal coil diameter of 1cm (leads 2x20mm).
The variable capacitor C4 should be air trimmer capacitor rating 4 to 30 pf or the closest to this value.
Connect the batteries in series place the best heat sink for TO39 case you can get and pack it all in a small plastic box. Enjoy ;)
Datasheet file1: Click here to download 2n3553 datasheet.
Park Aid Modification Circuit
Three-step beeps signal bumper-barrier distance, Infra-red operation, indoor use
This modification was designed on request: some people prefer an audible alert instead of looking at the LED display, making easier the parking operation. The original Park-aid circuit was retained, but please note that the input pins of IC2B, IC2C and IC2D are reversed. LEDs D5, D6 and D7, as also resistors R12, R13 and R14 are omitted. IC2B, IC2C and IC2D outputs drive resistors R15, R16 and R17 through D8, D9 and D10 respectively, in order to change the time constant of a low frequency oscillator based on the 555 timer IC4. This allows the Piezo sounder to start beeping at about 2 times per second when bumper-wall distance is about 20 cm., then to increase the beeps to about 3 per second when bumper-wall distance is about 10 cm. and finally to increase further the beeps frequency to more than 4 beeps per second when the distance is about 6 cm. or less.
Circuit diagram:
Park-Aid Modification Circuit Diagram
Parts:
R15_____________3K3 1/4W Resistor
R16___________330K 1/4W Resistor
R17___________470K 1/4W Resistor
R18___________150K 1/4W Resistor
C6______________1µF 63V Electrolytic or Polyester Capacitor
D8,D9,D10____1N4148 75V 150mA Diodes
IC4_____________555 Timer IC
BZ1___________Piezo sounder (incorporating 3KHz oscillator)
Source : www.redcircuits.com
Build a 16 LED Chaser Circuit Diagram
This 16 LED Chaser Circuit Diagram is a double direction flash. Similar to Digital Ping- Pong 1, there is a movement of a lit dot, up and down along the LEDs length.
16 LED Chaser Circuit Diagram
When the D16 lit the situation changes and there is a reverse movement. Lit D15-14 ……D16, is lit making circles when the circuit is under power. The IC1 is an unstable flip- flop supplying with stable frequency pulses (the frequency can be changed by TR1, adjusting the velocity of the LEDs up and down).
This frequency supplies the IC3 (which is a 4-Bit UP and DOWN counter) through 2 gates A-B of the IC2. The output counter supplies the IC4 that is the driver of the LEDs. The parts C- D of The IC2, make a R-S flip- flop, that changes situation, when the edge LEDs D1 and D16 lit.
We have an electronic limit for the situation change. In proportion the shape we make with the LEDs, we can have the proportionate optional result, making various effects.
Part List
R1= 100Kohms
R2= 220Kohms
R3= 470 ohms
TR1= 1Mohms
C1= 330nF 100V MKT
D1-16= LED 5mm
IC1= 555
IC2= 7400
IC3= 74193
IC4= 74154
3 Transistor Audio Amplifier Circuit
Description
Here is a little audio amplifier similar to what you might find in a small transistor radio. The input stage is biased so that the supply voltage is divided equally across the two complimentary output transistors which are slightly biased in conduction by the diodes between the bases. A 3.3 ohm resistor is used in series with the emitters of the output transistors to stabilize the bias current so it doesnt change much with temperature or with different transistors and diodes. As the bias current increases, the voltage between the emitter and base decreases, thus reducing the conduction.
Input impedance is about 500 ohms and voltage gain is about 5 with an 8 ohm speaker attached. The voltage swing on the speaker is about 2 volts without distorting and power output is in the 50 milliwatt range. A higher supply voltage and the addition of heat sinks to the output transistors would provide more power. Circuit draws about 30 milliamps from a 9 volt supply.
Circuit Diagram
Circuit Source - http://www.electronguide.com/circuits_pages/3_Transistor_Audio_Amp.html
Circuit Source - http://www.electronguide.com/circuits_pages/3_Transistor_Audio_Amp.html
Mobile Cellphone Battery Charger Circuit
Charging of the mobile phone, cellphone battery is a big problem while traveling as power supply source is not generally accessible. If you keep your cellphone switched on continuously, its battery will go flat within five to six hours, making the cellphone useless.
Parts
A fully charged battery becomes necessary especially when your distance from the nearest relay station increases. Here’s a simple charger that replenishes the cellphone battery within two to three hours. Basically, the charger is a current-limited voltage source. Generally, cellphone battery packs require 3.6-6V DC and 180-200mA current for charging. These usually contain three NiCd cells, each having 1.2V rating.
Current of 100mA is sufficient for charging the cellphone battery at a slow rate. A 12V battery containing eight pen cells gives sufficient current (1.8A) to charge the battery connected across the output terminals. The circuit also monitors the voltage level of the battery. It automatically cuts off the charging process when its output terminal voltage increases above the predetermined voltage level.
Circuit Diagram:- P1 = 20K
- P2 = 20K
- R1 = 390R
- R2 = 680R
- R3 = 39R-1W
- R4 = 27K
- R5 = 47K
- R6 = 3.3K
- R7 = 100R-1W
- C1 = 4.7uF-25V
- C2 = 0.01uF
- C3 = 0.001uF
- D1 = 5.6V-1W Zener
- D2 = 3mm. Red LED
- Q1 = SL100
- S1 = On/Off Switch
- B1 = 1.5vx8 AA Cells in Series
- IC1 = NE555 Timer IC
Timer IC NE555 is used to charge and monitor the voltage level in the battery. Control voltage pin 5 of IC1 is provided with a reference voltage of 5.6V by zener diode D1. Threshold pin 6 is supplied with a voltage set by P1 and trigger pin 2 is supplied with a voltage set by P2. When the discharged cellphone battery is connected to the circuit, the voltage given to trigger pin 2 of IC1 is below 1/3Vcc and hence the flip-flop in the IC is switched on to take output pin 3 high. When the battery is fully charged, the output terminal voltage increases the voltage at pin 2 of IC1 above the trigger point threshold.
This switches off the flip-flop and the output goes low to terminate the charging process. Threshold pin 6 of IC1 is referenced at 2/3Vcc set by P1. Transistor Q1 is used to enhance the charging current. Value of R3 is critical in providing the required current for charging. With the given value of 39-ohm the charging current is around 180 mA. The circuit can be constructed on a small general-purpose PCB.
For calibration of cut-off voltage level, use a variable DC power source. Connect the output terminals of the circuit to the variable power supply set at 7V. Adjust P1 in the middle position and slowly adjust P2 until LED (D2) goes off, indicating low output. LED should turn on when the voltage of the variable power supply reduces below 5V. Enclose the circuit in a small plastic case and use suitable connector for connecting to the cellphone battery.
Hand Held Transceiver dc Adapter Circuit Diagram
This Hand Held Transceiver dc Adapter Circuit Diagram provides a regulated 9-V source for operating a Kenwood TR-2500 hand-held transceiver in the car. The LM317T`s mounting tab is electrically connected to its output pin, so take this into account as you construct your version of the adapter. The LM317T regulator dissipates 2 or 3 W in this application, so mount it on a 1-x -2-inch piece of `is-inch-thick aluminum heatsink.
Hand Held Transceiver dc Adapter Circuit Diagram
Simple Adjustable Notch Filter Circuit Diagram
Adjustable Notch Filter Circuit Diagram. In applications where the rejected signal might deviate slightly from the null on the notch network, it is advantageous to lower the Q of the network. This insures some rejection over a wider range of input frequencies. The figure shows a circuit where the Q may be varied from 0.3 to 50. A fraction of the output is fed back to R3 and C3 by a second voltage follower, and the notch Q is dependent on the amount of signal fed back. A second follower is necessary to drive the twin `T` from a low-resistance source so that the notch frequency and depth will not change with the potentiometer setting.
Adjustable Notch Filter Circuit Diagram
Tracking Dual Output Bipolar Supply Circuit Diagram
This Tracking Dual Output Bipolar Supply Circuit Diagram is useful for a bench supply in the lab. Separate or tracking operation is possible. The regulators should be properly heatsinked. Tl is a 24-Vac wall transformer of suitable current capacity.
Tracking Dual Output Bipolar Supply Circuit Diagram
Build a Room Ioniser Circuit Diagram
This is a voltage multiplier circuit acting as an Room Ioniser Circuit Diagram. Its calculated to feed 220V from mains and the output is about 6KV. Caution should take with the circuit as can be dangerous due to mains. You can place a needle at the output 3cm long. Even you disconnect from mains, capacitors can be dangerous so make sure to discharge them by shorting their pins before you touch the circuit with hands.
Room Ioniser Circuit Diagram
Simple Flasher circuit diagram
Most of you asked about a LED flasher circuit.Here it is.Here I have used famous IC LM3909.This circuit operates with 1.5V
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Water Level Ditector Circuit
This is very useful circuit for us.Because by using this circuit you can control your water pump automatically.When the water goes down the trigger sensor level.The mot er will start automatically.After passing the threshold sensor level the mot er Will stop automatically.
Note
# When you fix sensors fix them tiddly.If not They will short together.
#This circuit works with 12V power supply.
Wireless Microphone circuit diagram
Wireless Microphone circuit diagramThe ambit of frequencies for the FM advertisement bandage is 90MHz (MHz = Megahertz or 90 actor cycles per second). Because the FM microphone has a capricious acquainted circuit, it can be acquainted to a quiet atom on your bounded FM advertisement bandage for the best reception. When the baby microphone aspect is addled by sound, it converts the audio to a change in accepted through resistor R1 (see schematic diagram).
This electrical change is amplified and eventually abundance modulates the transmitter. The manual ambit of the FM microphone is about 100 feet, depending on the ability of the antenna (properly acquainted or not) and the affection of the FM radio receiver.
Complete Room Securty System Circuit diagram
This simple circuit is called room security system circuit. The main purpose of this circuit is to secure your room in night. You need not any security guard. When any unwanted person wants to enter your room in night then this circuit raised alarm. On the other benefit, it is always activated on load shedding.
There are five separates parts in this circuit – regulated power supply, relay driver, door switching, alarm system and audio amplifier.
First section is regulated power supply. The output of IC 7809 is
regulated +9Volt which is converted from 9Volt unregulated power supply.
Capacitors are used for removing ripple. A full wave 9 volt transformer is connected in the input of this power section.
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There are five separates parts in this circuit – regulated power supply, relay driver, door switching, alarm system and audio amplifier.
First section is regulated power supply. The output of IC 7809 is
regulated +9Volt which is converted from 9Volt unregulated power supply.
Capacitors are used for removing ripple. A full wave 9 volt transformer is connected in the input of this power section.
The second part is relay driver. Q1 transistor is used for driving relay.
When the Q1 transistor is forward bias then the relay is ON and the
total circuit gets positive voltage from ac source. In the time of load
shedding relay is deactivated and the total circuit gets power from
6Volt Battery.
When the Q1 transistor is forward bias then the relay is ON and the
total circuit gets positive voltage from ac source. In the time of load
shedding relay is deactivated and the total circuit gets power from
6Volt Battery.
The third part is door switching. When C1 capacitor’s two terminals are short, transistor Q2 is reversed
biased. So Q2 transistor is OFF. When C1 capacitor’s two terminals are
open, transistor Q2 is forward biased. So Q2 transistor is ON. For this
reason IC UM66 is ON and it
generates music which is feed another two transistors Q3 and Q4. A
speaker is connected with collector of the transistor Q4 as circuit
diagram.
biased. So Q2 transistor is OFF. When C1 capacitor’s two terminals are
open, transistor Q2 is forward biased. So Q2 transistor is ON. For this
reason IC UM66 is ON and it
generates music which is feed another two transistors Q3 and Q4. A
speaker is connected with collector of the transistor Q4 as circuit
diagram.
150 watts power amplifier circuit
Amplifier circuit is 150 watts power amplifier circuit is quite simple.
This circuit requires only 5 pieces of transistors as the main component of reinforcement. There is no equalizer option on this amplifier circuit because it can be said of this series is very simple, so do not you compare it with that sold in the market which are usually equipped with various sound system and equalizer settings.
This circuit requires only 5 pieces of transistors as the main component of reinforcement. There is no equalizer option on this amplifier circuit because it can be said of this series is very simple, so do not you compare it with that sold in the market which are usually equipped with various sound system and equalizer settings.
But to add to your collection circuit, this circuit is fairly easy and inexpensive to make and maybe one day you may need as a weak signal booster from your electronic circuit. Or you can also make this amplifier as an amplifier of high frequency signal from the output circuit animal repellent and I guarantee the results are very satisfactory.
Power supply required is two-polarity power supply is + - 45 volts. Maximum power that can be obtained by this amplifier circuit is around 150 watts. As the volume control you can add potensio or variable resistor 10 Kohm in series at the input. Use dispasi loudspeaker with 150 watts power. Use a heatsink on the transistor-transistor driver loudspeaker or amplifier late as Q1 and Q2.
USB Powered Audio Power Amplifier Circuit Diagram
This circuit of multimedia speakers for PCs has single-chip-based design, low-voltage power supply, compatibility with USB power, easy heat-sinking, low cost, high flexibility and wide temperature tolerance. At the heart of the circuit is IC TDA2822M. This IC is, in fact, mono-lithic type in 8-lead mini DIP package. It is intended for use as a dual audio power amplifier in battery-powered sound players. Specifications of TDA2822M are low quiescent current, low crossover distortion, supply voltage down to 1.8 volts and minimum output power of around 450 mW/channel with 4-ohm loudspeaker at 5V DC supply input.
An ideal power amplifier can be simply defined as a circuit that can deliver audio power into external loads without generating significant signal distortion and without consuming excessive quiescent current. This circuit is powered by 5V DC supply available from the USB port of the PC. When power switch S1 is flipped to ‘on’ position, 5V power supply is extended to the circuit and power-indicator red LED1 lights up instantly. Resistor R1 is a current surge limiter and capacitors C1 and C4 act as buffers. Working of the circuit is simple. Audio signals from the PC audio socket/headphone socket are fed to the amplifier circuit through components R2 and C2 (left channel), and R3 and C3 (right channel).
Circuit diagram:
USB Powered Audio Power Amplifier Circuit Diagram
Potmeter VR1 works as the volume controller for left (L) channel and potmeter VR2 works for right (R) channel. Pin 7 of TDA2822M receives the left-channel sound signals and pin 6 receives the right-channel signals through VR1 and VR2, respectively. Ampl i f ied signals for driving the left and right loudspeakers are available at pins 1 and 3 of IC1, respectively. Components R5 and C8, and R6 and C10 form the traditional zobel network. Assemble the circuit on a medium-size, general-purpose PCB and enclose in a suitable cabinet. It is advisable to use a socket for IC TDA2822M. The external connections should be made using suitably screened wires for better result.
Author: T.K. Hareendran - Copyright: EFY Mag
led light running arrows showing the position circuit and explanation
This
is a led light running circuit with a number generated from IC
CD4093, CD4520 and CD4094.This circuit can adjust the speed with
resistors R1.When entering the power supply to the circuit IC1. A nand
gate IC Oscillator generator circuit is connected to the input signal
generator to pin 1 of IC2 and pin 3 of the IC3.When receiving the
signal from IC1 IC2 will serve up the signal from the logic into the
binary.Then sent to the pin 5 and pin 6 of IC1, IC1, which will process
a nand gate.The IC3 is the signal from IC1 to processing and export
of pin 4, 5, 6 and 7.Then entered into the base of the transistor pins
Q1-Q4.Any work on the transistor connected to the LED pin collector
will glow out come.For the format of the 17 LED Lights, arranged as a
form of directional arrows.
source: www.eleccircuit.com
555 TLC555 Relay Driver Circuit
Many integrated circuits have undocumented features or abilities. This is one of them. The TLC555 output (pin 3) can sink a 100mA load to 1.28V. The open drain transistor reset (pin 7) can sink 100mA to 1V. Tying both lines together is permissible because they are logically the same polarity and this potentially doubles the sink current ability to 200mA. This is ideal for driving my 133mA relay coil.
The input also has the undocumented, but better known, feature of a Schmitt trigger that provides positive switching.
Protoboard setup
Output current rating (pin 3): TLC555 vs. NE555
While it can be seen that the NE555 has the higher current rating, its saturation voltage is grossly inferior and this is a detriment in driving loads without excessive voltage drop. Also it can be seen that the TLC555 is much like TTL in that its sourcing ability is far less than its sinking ability. However for driving a relay, we are interested only in current sinking properties.
Relay out of my junk box
This is a 40A automotive relay (contactor) that I selected for this application. Since its coil current exceeds the TLC555 output sink current rating, it is a good candidate. Manufacturer or part number is unknown.
Schmitt trigger input
The trigger input (pin 2) and the threshold input (pin 6) pins are tied together—this is commonly done. With a 12V supply, the upper threshold is 8V and the lower is 4V. The two voltage levels, being far apart, make a great Schmitt trigger. This may be driven directly by 4000series CMOS logic that is also powered via 12V.
To make it compatible with TTL logic levels, simply add the two resistors that are shown in the schematic. This loads down the internal divider to a lower voltage. The calculated levels are approx. 1.4 and 2.8V respectively.
Testing the performance
The standard 555 saturates poorly (2.5V) at 200mA and its reset line (pin 7) is not specified above 15mA, so it is not recommended. The intersil 7555 is a very low power device, so that is not recommended either.
For the future
Read Full article[...]
The input also has the undocumented, but better known, feature of a Schmitt trigger that provides positive switching.
555 Relay Driver Schematic
Protoboard setup
Output current rating (pin 3): TLC555 vs. NE555
| (Vcc = 15V) | TLC555 | NE555 |
|---|---|---|
| Source current | 10mA | 200mA |
| Source mode saturation voltage | Vcc-0.8V | Vcc-2.5V |
| Sink current | 100mA | 200mA |
| Sink mode saturation voltage | 1.28V | 2.5V |
Relay out of my junk box
This is a 40A automotive relay (contactor) that I selected for this application. Since its coil current exceeds the TLC555 output sink current rating, it is a good candidate. Manufacturer or part number is unknown.
- Contact rating: 40A (from memory)
- Coil resistance: 90Ω cold
- Coil current: 133mA
- Coil power: 1.6W
- Coil voltage: 12V
- Pickup voltage: 4.8V cold
- Dropout voltage: 2.1V cold
- Operate time: 4.5mS
Schmitt trigger input
The trigger input (pin 2) and the threshold input (pin 6) pins are tied together—this is commonly done. With a 12V supply, the upper threshold is 8V and the lower is 4V. The two voltage levels, being far apart, make a great Schmitt trigger. This may be driven directly by 4000series CMOS logic that is also powered via 12V.
To make it compatible with TTL logic levels, simply add the two resistors that are shown in the schematic. This loads down the internal divider to a lower voltage. The calculated levels are approx. 1.4 and 2.8V respectively.
Testing the performance
- Output saturation voltage:
- 0.617V @ 133mA
- 1.043V @ 200mA
- TTL high level threshold: 3.0V
- TTL low level threshold: 1.6V
The standard 555 saturates poorly (2.5V) at 200mA and its reset line (pin 7) is not specified above 15mA, so it is not recommended. The intersil 7555 is a very low power device, so that is not recommended either.
For the future
- Assorted relay driver circuits
- 555 Voltage doubler relay driver circuit
- Relay economy circuits
555 datasheet
Backlight Driver for WLED Display Circuit
This is a design circuit for WLED-display backlight driver circuit. This circuit can be used to power WLEDs by replacing the voltage-feedback network with a series current-sense resistor, R3, and the WLED strings. This circuit uses The TPS6108x that drive some series WLEDs in parallel for backlighting larger displays. This is the figure of the circuit;
The feedback of this circuit is The voltage across the current-sense resistor. This feedback provides regulation. This circuit uses 1.2-V feedback voltages. The power lost of this circuit because of R3 is Plost= Iwled*Iwled*R3 = 1.2V*Iwled. The TPS6108x converters is equipped with an SS pin that can provide variable soft startup for boosted voltage regulation applications. Beside that, The SS pin can be used to lower the FB-pin reference voltage and to reduce sense-resistor power loss in aWLED current-regulation application. The FB-pin reference voltage can be lowered by connecting a resistor, R1, from the SS pin to GND. WLED current can be calculated by following equation:
Iwled=(Iss*R1)/R3
Analog dimming is provided by A second resistor, R2, that is connected with the FET and Q1 in series connection and parallel connection with R1. Those connections will lower the regulated FB-pin voltage across the sense resistor.
[Schematic circuit source: Texas Instruments Application Note]
Audio phase shift oscillator Circuit Diagram
Here is a phase-shift audio oscillator with excellent distortion characteristics thanks to “softened” diode limiting provided by the 1N914 and resistor divider and degenerated gain provided by the 68 ohm emitter resistor. For minimum distortion, increase the 68 ohm resistor to a point just below where oscillation stops. A simple buffer may be added for driving lower impedance loads.
The output amplitude will be about 5 volts p-p but one of the 1N914’s 10k divider resistors may be changed for a different output amplitude. The circuit will work well with a power supply voltage other than 9 volts but the 68 ohm resistor may need adjustment
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