http://freecircuitdiagram.com Free electronic circuit, schematic diagram, circuit diagram Sat, 13 Mar 2010 03:07:14 +0000 http://wordpress.org/?v=2.8.5 en hourly 1 http://freecircuitdiagram.com/2010/01/14/digital-ic-transmits-both-fm-and-am-simultaneously/ http://freecircuitdiagram.com/2010/01/14/digital-ic-transmits-both-fm-and-am-simultaneously/#comments Thu, 14 Jan 2010 01:17:48 +0000 Circuitguy http://freecircuitdiagram.com/?p=1339 The transmitters that either working in FM or in AM is familiar. This is transmitters circuit that can transmit both FM and AM signal simultaneously at two different frequencies FM in 100Mhz and Am in 20 MHz. Here is the circuit: To transmit the FM signal, this circuit uses the 5th harmonics of the fundamental 20Mhz. [...]]]> http://freecircuitdiagram.com/2010/01/14/digital-ic-transmits-both-fm-and-am-simultaneously/feed/ 0 http://freecircuitdiagram.com/2010/01/14/fm-transmitter-using-logic-gates/ http://freecircuitdiagram.com/2010/01/14/fm-transmitter-using-logic-gates/#comments Thu, 14 Jan 2010 01:12:19 +0000 Circuitguy http://freecircuitdiagram.com/?p=1336 This is a FM Transmitter circuit. This circuit uses logic gates. This transmitter circuit has a RF oscillator. This oscillator uses 10.7Mhz ceramic filter and inverter N2 to drive the parallel combination of N4 to N6 through N3. Here is the circuit: The output impedance will be low because these inverters are in parallel, so an [...]]]> http://freecircuitdiagram.com/2010/01/14/fm-transmitter-using-logic-gates/feed/ 0 http://freecircuitdiagram.com/2009/05/30/another-small-single-chip-fm-transmitter/ http://freecircuitdiagram.com/2009/05/30/another-small-single-chip-fm-transmitter/#comments Sat, 30 May 2009 12:58:53 +0000 Circuitguy http://freecircuitdiagram.com/?p=885 This FM transmitter circuit is small, similar to our previous single chip FM  transmitter, but this FM transmitter is monophonic. You can see in the circuit’s schematic, the left and right signals is mixed before modulate the radio frequency. Here is the schematic diagram of the circuit:   The core of this FM transmitter circuit is a [...]]]> http://freecircuitdiagram.com/2009/05/30/another-small-single-chip-fm-transmitter/feed/ 0 http://freecircuitdiagram.com/2008/10/28/single-transistor-wireless-microphone-fm-transmitter/ http://freecircuitdiagram.com/2008/10/28/single-transistor-wireless-microphone-fm-transmitter/#comments Tue, 28 Oct 2008 07:25:02 +0000 Circuitguy http://freecircuitdiagram.com/?p=487 This wireless microphone circuit uses only a single transistor, with few additional passive components. This FM transmitter is very compact and need only a single cell 1.5Volt battery, even works on 1.2V rechargeable battery. Here is the schematic diagram of the circuit: The transmission range could be between 30-50m radius in open air, and practically depends [...]]]> http://freecircuitdiagram.com/2008/10/28/single-transistor-wireless-microphone-fm-transmitter/feed/ 0 http://freecircuitdiagram.com/2008/10/28/two-transistors-wireless-microphone-fm-transmitter/ http://freecircuitdiagram.com/2008/10/28/two-transistors-wireless-microphone-fm-transmitter/#comments Tue, 28 Oct 2008 05:51:42 +0000 Circuitguy http://freecircuitdiagram.com/?p=483 Please be warned if operating this circuit might violate the regulation of your country, because this FM transmitter circuit radiate strong radio frequency to the environment. This wireless microphone is very sensitive, pick up every sound in the 20m radius, and transmit the radio signal up to 2 kilometers in open air. Here is the [...]]]> http://freecircuitdiagram.com/2008/10/28/two-transistors-wireless-microphone-fm-transmitter/feed/ 0 http://freecircuitdiagram.com/2008/10/28/single-chip-stereo-fm-transmitter-circuit-a-very-compact-design/ http://freecircuitdiagram.com/2008/10/28/single-chip-stereo-fm-transmitter-circuit-a-very-compact-design/#comments Tue, 28 Oct 2008 02:53:13 +0000 Circuitguy http://freecircuitdiagram.com/?p=478 ROHM (www.rohm.com) is originally a resistor producer company, but finally expand their business and produce monolithic IC, and this one used in our circuit is the example. The internal structure of this FM transmitter integrated circuit consist of stereo modulator that creates a stereo composite signal, an FM modulator that modulate a carrier frequency with [...]]]> http://freecircuitdiagram.com/2008/10/28/single-chip-stereo-fm-transmitter-circuit-a-very-compact-design/feed/ 0