DiscoverCircuits.com, has 28,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.
We make every effort to link to material posted by the designer. 
Please let us if you would like us to link to your design.

• 175KHz INDUCTIVE PULSE RECEIVER
  This circuit is discussed in more detain in the Experimenters Journal. The receiver’s six inch diameter coil detects the ring signal from the above transmitter and use a single NPN transistor to provided enough amplification for the signal to be easily viewed on an oscilloscope.

$10 Receiver has MicroVolt Sensitivity:  08/18/94 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)  The three-transistor circuit in Fig 1 costs less than $10 to build, uses commonly available components, and consumes less than 10 mA from a single 9V battery. If you wind coil L1, as the figure shows, the circuit receives signals in the 5- to 15-MHz short-wave band. You can add turns to or subtract turns from L(or change C2) to receive other frequencies....  

µC Provides Wireless Keypad Control:  10/08/98 EDN-Design Ideas / (Circuit / schematic design added 6/06) Portable systems, such as telephone handsets, make extensive use of low-dropout (LDO) regulators. These components provide noise-sensitive parts with a stable power-supply line. When a telephone enters standby mode, most of the circuits go to sleep by disabling the LDO's outputs. Operating current thus drops to a minimal level. When a user starts to dial a number, the LDO receives an enable signal and immediately delivers the nominal...

1 Transistor FM Receiver:  (added 8/03)

136 kHz Direct Conversion Receiver:  (Electronic Schematic / circuit added 4/02)

40 Meter Popcorn Superhet Receiver:  This schematic is a relatively low-cost CW superhet receiver with a 4.00 MHz Intermediate frequency. There is no AGC or RF gain control, however this receiver has good large signal handling capability. This receiver uses just 6 bipolar transistors and an op amp for reasonable volume into headphones. Much of the ideas/design of the various stages must be credited to Wes Hayward as I borrowed heavily from his previous work and through ideas obtained by discussion. If one were to homebrew the diode ring mixers, indeed this would be a very low cost receiver giving reasonable performance which outperforms any NE602 based superhet receivers that I have built or listened to ... (Electronic circuit design added 02/05)

40m Direct Conversion Receiver:  (added 8/03)

41 Meter Popcorn Superhet Receiver:  This schematic is a relatively low-cost CW superhet receiver with a 4.00 MHz Intermediate frequency. There is no AGC or RF gain control, however this receiver has good large signal handling capability. This receiver uses just 6 bipolar transistors and an op amp for reasonable volume into headphones. Much of the ideas/design of the various stages must be credited to Wes Hayward as I borrowed heavily from his previous work and through ideas obtained by discussion. If one were to homebrew the diode ring mixers, indeed this would be a very low cost receiver giving reasonable performance which outperforms any NE602 based superhet receivers that I have built or listened to ... (Electronic circuit design added 02/05)

42 Mc Band to 88 Mc Band (retrofit Converter) Project:  (Electronic Schematic / circuit added 4/02)

45-860MHz Radio receiver Based on UV916-tuner:  This receiver use a TV-tuner, a simple radio-circuit and a interface to a computer.  The computer control (set) the receiving frequency from 45-860MHz. The purpose of this project is to learn about tuners, it's a pre-project for my Spectrum analyzer project. The UV916 or UV918 tuner is easy to find in broke TV or VCR:s. It is a common tuner...   (Electronic circuit added 4/05)

49MHz Walkie Talkie:  Lots of people are requesting walkie-talkie and RF remote control schematics, so here is some. Building these circuits needs special equipment and expertise in RF circuits. If you are going to experiment with these circuits, please note that I did not build them, and I am not able to help you with any details. If you have no experience in RF, I suggest that you choose the easy way and buy a ready-made RF module. Otherwise you can realize you have an exact copy of a circuit in your hand, still it doesn't work the way it should.  (added 8/03)

50 MHz to 146 MHz Converter:  (added 2/05)

80 Meter CW ARDF Receiver:  (added 8/03)

80m Direct Conversion Receiver #1:  (added 2/05)

80m Direct Conversion Receiver #2:  (added 8/03)

A 70-W S-Band Amplifier For MMDS and Wireless Data/Internet Applications (12/11/00) :  Application Note - California Eastern Laboratories - Doc #932  (Circuit / schematic design added 6/06)

AGC Amplifier features 60 dB dynamic range:  08/04/05 EDN Design Ideas  / (added 8/05)  Using discrete components only, build an audio-band AGC.

AM Radio PreAmplifier:  (Electronic Schematic / circuit added 4/02)

AN-502: Designing a Superheterodyne Receiver using an IF Sampling Diversity Chipset:  AN-502 - Analog Devices Application Notes  (Circuit / schematic design added 6/06)  The AD6600/AD6620 Chipset Simplifies Receiver Design

AN714: Wireless Home Security Implementing Keeloq® and the Picmicro® Microcontroller:  Microchip Application Note - Published 12-Oct-99   (Circuit / schematic design added 6/06)

AN758: Using the MCP2150 to Add IRDA® Standard Wireless Connectivity:  Microchip Application Note - Published 4-Jun-01   (added 2/06)

AN959: Using the PIC16f639 Mcu for Smart Wireless Applications:  Microchip Application Note - Published 10-Nov-04   (Circuit / schematic design added 6/06)

Audio Circuit:  (Electronic circuit design added 02/05)

AV (Audio/Video) Wireless Transmitter:  (Circuit / schematic design added 6/06)

Bipolar Regenerative Receiver:  (added 8/03)

Build your own Superheterodyne Receiver:  08/01/96 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) Cell phones aren't the only devices to benefit from ever- smaller and more highly integrated communications-IC technology. The simple, three-IC superheterodyne radio in Figure 1 can receive stations in the 4.5- to 10-MHz range from around the world with only a 10-ft antenna. A superheterodyne radio works by mixing the incoming RF signal with a local-oscillator (LO) signal to produce an IF. We don't need to spell it out. The circuit then filters, amplifies, and diode-detects the IF signal to reproduce the audio signal contained in the RF input. The transformer-capacitor circuit at the input provides impedance matching to the antenna; the T2-C2A tuned circuit provides rough preselection for the 4.4- to 10-MHz RF signal. IC1, a Philips NE602, contains....