This is a ultrasonic motion detector (or movement detector) circuit. The circuit claimed has a high movement sensitivity. Even air moving (hot air rising, wind blowing) will trigger it when the trimpot is set near the most sensitive position. The transmitter sends out a steady ultrasonic tone at 40kHz. At this frequency the wavelength is… Read More »
This is the circuit diagram of DOD FX75 Flanger guitar effect pedal. The circuit drawn by Fabian P. Hartery. Featuring a Width control and two output jacks, the FX75 was much more versatile than its predecessor, but the flanging effect it could provide was still not very intense. That said, chorus-like washes of flange can… Read More »
This is the schematic diagram of Electro-Harmonix Small Stone Phaser guitar effect pedal. The Small Stone is somewhat special in applying Operational Transconductance Amplifiers (OTA”s) for phase shift stages rather of opamps with variable resistors. All of the IC”s are house marked EH1048, but could be replaced with CA3094 that is a combination of an… Read More »
The following diagram is the schematic diagram fo Car Horn, you may try this circuit for your car modification… 🙂 Components List: R1 = 68K R2 = 2K2 R3 = 56K R4 = 3K3 R5,R6 = 4K7 R7 = 10K Pot/trimpot C1,C2 = 22nF C3,C5 = 100nF C4 = 1nF C6 = 220uF/25V IC1,IC2 =… Read More »
This is the design diagram of 5 band graphic equaliser circuit build using operational amplifier chips, the NE5532 or LM833. The op-amp ICs is a good choice because of inexpensive and comes with fairly good quality output. Each IC contains dual op-amps circuit, so you will need 4 ICs of NE5532 or LM833 to build… Read More »
The following diagram is the FM transmitter circuit with FM transmision up to 4W. Voltage supply for this circuit is 12-16V with current consumption of 100-400mA. This circuit works with frequency of emission range of 88-108MHz. Transistor 2N2219 used as the main signal amplifier. 4 Watts FM Transmitter circuit design: Components List: R1, R2 =… Read More »
The following diagram is the schematic diagram of 4 transistors FM transmitter circuit designed by Paul K. Sherby. Components List: R1,R2,R8 = 1K R3 = 100K R4 = 150K R5,R7 = 10K R6 = 220 ohm R9 = 10 ohm P1 = 5K trimpot D1 = 1N4002 Q1,Q2 = 2N3904 Q3,Q4 = 7001, NTE123AP C1… Read More »
In the above circuit diagram, a CMOS operational amplifier (op-amp) controls the current via a P-Channel HEXFET power transistor (IRF9520) to maintain a constant voltage across R1. The current is given by: 1 = VREF/R1. The benefits of this configuration are:
This is the positive voltage regulator circuit with PNP Boost transistor: The IC8211 presents the voltage reference and regulator amplifier, while Q1 will be the series pass transistor. R1 defines the output current of the IC8211, while C1 and C2 present loop stability and as well act to suppress feedthrough of input transients to the… Read More »