Here the simple schematic of multitone siren alarm circuit. This multitone siren is effective for reverse horns, burlgar alarms, and many others. It generates five various audio tones and is much more earcatching than a single-tone siren.
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 »
This is a A/B Box switch pedal schematic with two inputs and one output and featured with dual operational amplifier modules. This circuit was designed by Rick Barker. This A/B Box effect was originally designed for switching between different harmonica mics. This A/B Box featured low noise dual preamp for better performance.
The following diagram is the Theremin music instrument effect. A guitar or instrument amplifier is an ideal companion unit for the theremin; either one allows bass or treble boost, as desired, and fuzz (distortion) or reverberation (if these features are incorporated in the amplifier”s circuit). Simply provide a suitable cable plug and connect the theremin”s… Read More »
This is the scheme diagram of passive surround circuit. Passive surround doesn’t need any active components and power supply to make the circuit works. The circuit just need the combination of resistors and electrolytic capacitors. Circuit Notes: This passive surround circuit MUST be connected after power amplifier module. Use full range type of loudspeaker. Do… Read More »
The following image is the scheme diagram of six LED stereo VU display circuit which build using Dot/Bar Display Driver IC LM3915. This VU display should be connected before amplifier module circuit. You may connect this circuit at pre-amp output, tone control input/output or equaliser input/output. This circuit powered with 12V DC supply. About LM3915:… Read More »
The following diagram is the circuit diagram of 20 band stereo graphic equaliser which will controlling the audio signal in specific frequency range. The power supply used for this circuit is symmetrical (dual polarity) type, 15V DC.
This is a very simple FM receiver which build based on one transistor only. No chip or another active component. The output is connected to earphones, you need an amplifier circuit if you want to listen the radio with a loudspeaker.
Here is the AM Radio receiver circuit diagram based on old single IC MK484. Components List: R9, R10_________ 6R8 R6_____________ 100R R3_____________ 1K R1_____________ 4K7 R7_____________ 5K6 R4_____________ 10K R2_____________ 100K R5_____________ 150K R8_____________ 820K Pot_____________ 10K log pot Coil & ferrite bar set C7______________ 470p ceramic C, C4, C5, C6_____ 470nF monoblock C2______________ 100nF… Read More »