Switched ON Bike Lamp circuit diagram:

Component part list:

This switched ON bike lamp circuit was primarily intended to permit automatic switch-on of push-bike lights when it gets dark. Naturally, it might be applied for any other purpose involving one or more lamps to be switched on and off depending of light intensity. Power could be supplied by any kind of battery suitable to be fitted in your bike and having a voltage within the 3 to 6 Volts range. The Photo resistor R1 needs to be fitted into the box containing the total circuit, but a hole should be created in a convenient side of the box to allow the light hitting the sensor. Trim R2 until the desired switching threshold is reached. The setup will require some experimenting, but it ought to not be hard.

Bike Lamp circuit notes:

• In this circuit, the maximum electric current and voltage delivered to the lamp(s) are limited primarily by R6 (that can’t be omitted if a clean and reliable switching is expected). Consequently, the Ohm’s Law should be applied to calculate the ideal voltage and current values of the bulbs.
• At 3V supply, R6 value may be lowered to 1 or 0.five Ohm and the operating voltage of the bulbs should be chosen accordingly, by applying the Ohm’s Law. Example: Supply voltage = 3V, R6 = 1R, total current drawing 600mA. Decide on 2.2V bulbs as the voltage drop caused by R6 will probably be 0.6V.
• At 3V supply, R5 value should be changed to 100R.
• As an example: at 6V supply, one or much more 6V bulbs having a total current drawing of 500mA can be applied, but for a total current drawing of 1A, 4.5V bulbs need to be chosen, as the voltage drop across R6 will become 1.5V. In this case, R6 should be a 2W type.
• Stand-by current is much less than 500uA, provided R2 value following trimming is set at about 5K or greater: for that reason, the power switch SW1 could be omitted. If R2 value is set below 5K the stand-by current will enhance substantially.

Switched ON Bike Lamp circuit source: redcircuit.com

The post Switched ON Bike Lamp appeared first on Circuit Schematic Diagram.

Simple and cheap, the circuit built based on well-known IC regulator LM317 with current booster of power transistor 2N3782. Don’t forget to add heatsink especially for power transistor 2N3782.

A switching power supply is a type of power supply that uses electronic switches to control the flow of electrical energy. Unlike linear power supplies, which regulate the output voltage by dissipating excess energy as heat, switching power supplies are more efficient because they switch the input voltage on and off at a high frequency.

Switching power supplies are widely used in electronic devices, computers, telecommunications equipment, LED lighting, and other applications where efficiency, size, and weight are critical considerations. However, they can introduce electrical noise, and careful design is required to minimize electromagnetic interference (EMI).

The post 3A Switching Power Supply Regulator appeared first on Circuit Schematic Diagram.

Here is the remote control tester circuit. This circuit is really a simple and easy tester for verifying the basic operations of an infrared remote control unit. It is low-cost and very easy to construct.

The tester is designed around infrared receiver module TSOP1738. Operation of the remote control is identified by a tone from the buzzer. The circuit is sensitive and has a range of about 5 metres. The integrated IR receiver detects, amplifies and demodulates IR signals from the remote control unit. The piezobuzzer connected at its output sounds to tell us the existence of transmission from the remote control unit.

As displayed in above circuit diagram, output pin 3 of IR receiver module TSOP1738 (IRX1) normally stays high and the piezobuzzer is in silent mode. When the IR module IRX1 receives an infrared signal, its output is going low and, because of this, the piezobuzzer sounds to signify the reception of transmission from the remote (for example television remote control unit).

Power supply for the circuit is taken from the mains making use of a capacitive potential dropper, a half-wave rectifier, a shunt regulator and related parts. Ensure that capacitor C1 is of X2 type. Work with a appropriately small enclosure for making the unit handy.

Assemble the circuit on a general purpose PCB and enclose inside a box. Ensure that the IR receiver module is positioned around the front panel of the box/cabinet so that it can get the IR signals easily. Well, before soldering/connecting the shunt regulator and IR module, please check up the following TL431 and TSOP1738 pin configuration.

The post Remote Control Tester appeared first on Circuit Schematic Diagram.

Parts 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.)

Nothing critical here. Detail instruction: go to this page

My Notes:

• The original circuit source said that the diode is 1N4003 (3A diodes). That’s is a mistake, the correct diodes should be 1N5401. 1N4003 is 1A diode with higher voltage.
• Schottky diodes is recommended.

The post Current Output Multiplier for 78xx Regulator appeared first on Circuit Schematic Diagram.

Components list:
R1 = 100K Ohms
R2 = 10 Ohms
R3 = 47K Ohms
R4 = 220 Ohms
C1 = 4.7uF/16V
C2, C5 = 1nF
C3 = 10 – 40 pF trimmer capacitor
C4 = 4.7pF

Q1 = 2N3906 PNP transistor
Q2, Q3, Q4 = 2N3904 NPN transistor
L1 = 4-5 turns of 22 ga. magnet wire close wound around 1/8″ non-conductive core
Antenna = 10 to 12″ hookup wire

With wide voltage supply (3-9v), this FM tracking transmitter can used 3V or 9V battery to operate.

The post 4 Transistor FM Tracking Transmitter appeared first on Circuit Schematic Diagram.

This is the circuit diagram of white line follower toy. The actuator of the toy is the DC motor. This circuit can be used for?a toy car to follow a white?line, this circuit also known as very simple robot: “line follower without microcontroller”. The motor is either a?3v type with gearing to?steer the car or a rotary?actuator or a servo motor.

How the circuit work..?

When equal light is detected by the photo resistors the voltage on the base of the first transistor will be mid rail and the circuit is adjusted via the 2k2 potensiometer so the motor does not receive any voltage. When one of the LDR’s receives more (or less) light, the motor is turned on / activated. And the same thing will be happen when the other LDR receives less or more light.

You can see the below video as the result of this circuit project:

The post White Line Follower appeared first on Circuit Schematic Diagram.

The circuit above is complete circuit contains tube amplifier circuit diagram and power supply circuit diagram. To make the stereo channel amplifier, build the similar amplifier circuit only and connect to the power supply using parallel connection with another same amplifier.

The tube EL34 is a thermionic valve or vacuum tube of the power pentode type. It has an international octal base (indicated by the ‘3’ in the part number) and is found mainly in the final output stages of audio amplification circuits and was designed to be suitable as a series regulator by virtue of its high permissible voltage between heater and cathode and other parameters. The American RETMA tube designation number for this tube is 6CA7. The Russian analog is 6P27S (Cyrillic: 6?27C).

The tube EL34 was widely used in higher-powered audio amplifiers of the 1960s and 1970s, such as the very popular Dynaco Stereo 70 and the Leak TL25(mono) and Stereo 60, and is also widely used in high-end guitar amplifiers because it is characterized by greater distortion (considered desirable in this application) at lower power than other octal tubes[citation needed] such as 6L6, KT88 or 6550.

20W power tube/valve amplifier circuit diagram with EL34

The post 20W Power Tube Amplifier with EL34 appeared first on Circuit Schematic Diagram.

Vcc – Pin 1 IC1
+12v – Pin 8 IC2, IC3, IC4
-12v – Pin 4 IC2, IC3, IC4
Ground – Pin 8 IC1

IC1 – 4049 CMOS Hex Inverting Buffer
IC2, 3, 4 – 5532 Dual Low-Noise OpAmp
D1, 2 – 1N4001
D3, 4, 5, 6, 7 – 1N4148
All 1uf caps 50v all others 25v unless
marked otherwise.
All resistors 1/4W, 5%

Channel 2 is identicle to Channel 1, and uses IC4b for the clipping meter and IC3 for the input/output driver. The input impedance of the TubeHead is about 20k ohms, which is consistant with most gear like Synths, Effects Processors, Mixers, EQs, and so on. 20k is too low for a proper match with high impedance sources like guitar pickups, but a few minor changes take care of this. To use the Tube Head as a instrument pickup preamp, remove the 47k* resistor and the 20pf capacitor from the feedback loop of the driving Op-Amp. Then change the 47k” resistor to 680k and the 22k resistor in the feedback loop of the driving OpAmp to 100k. Now the Tube Head can be used to warm up a cold sounding guitar amp or just provide a great preamp tone.

Designed/Manufactured by PAiA Electronics

Download Tube Head circuit + components list and explanation in pdf file:

Tube Head Pre-amp Circuit

1 file(s) 16.37 KB

Download Circuit Diagram

The post Tube Head Pre-amp appeared first on Circuit Schematic Diagram.

Preview:

Preamp Section:

Download the complete scheme of Orange 125MK3 Guitar Mods from the following link:

125MK3 Guitar Mods Scheme

1 file(s) 177.19 KB

Download

The post Orange 125MK3 Guitar Mods appeared first on Circuit Schematic Diagram.

Components List:
R1,R2,R3 = 22M Ohms
R4 = 2.2M Ohms
C1 = 0.47uF/250V Mylar caps
D1 = 1N914, NTE519, or other small signal diode
Q1 = 2N3904, NTE123AP
Q2 = 2N3906, NTE159
Q3 = IRF510, NTE2382,? MosFet

This kind of circuit speaks for itself. While the phone line is okay, Q1 works as a short that has a extremely high resistance/ohms value via R1, R2, and R3 for a total close to 66 MegaOhm, so it is very high. When the phone line is cut (open), it triggers the MosFet (Q3) via transistor Q2 to drive the load. Replacements are acceptable, not one of the parts are crucial.

The ‘LOAD’ can be anything you like. A lamp, relay, motor, tape-recorder, stereo, security system, or anything else.

Remember that telephone providers do not like to have anything ‘directly’ connected to their wire connections for apparent reasons, so work with this circuit at your own risk. If you want to experiment with it safely, work with an Opto-Isolator or something…

Circuit designed by Tony van Roon

The post Cut Phone Line Detector appeared first on Circuit Schematic Diagram.