Showing posts with label radio. Show all posts
Showing posts with label radio. Show all posts
Tuesday, May 14, 2013
Jeep Grand Cherokee Radio Adaptor Wiring Harnesscircuit Schematic
Help With Fog Light Wiring Problem Ford Mustang Forums.
Cr4 Thread Wiring Harness Conversion U S To European.
Switching The Light And Using The Pull Chain For The Fan Single.
Two Way Light Switch Wiring.
Jeep Grand Cherokee Radio Adaptor Wiring Harness Circuit Schematic.
Wiring Trailer Lights.
Wiring A Light Fitting.
Headlight Wiring 12 Volt Lights On A 24 Volt System Service.
Wiring A Switch With Light In Middle Of Circuit.
Light With Outlet 2 Way Switch Wiring Diagram.
Tuesday, April 9, 2013
Build a Radio Wave Alarm
This simple circuit is sure to have the police beating a path to your door- however, it has the added advantage of alerting you to their presence even before their footsteps fall on the doormat.
Simple Radio Wave Alarm Circuit Diagram :
Simple Radio Wave Alarm Circuit Diagram :
Notes :
- The circuit transmits on Medium Wave (this is the small problem with the police). IC1a, together with a sensor (try a 20cm x 20cm sheet of tin foil) oscillates at just over 1MHz. This is modulated by an audio frequency (a continuous beep) produced by IC1b. When a hand or a foot approaches the sensor, the frequency of the transmitter (IC1a) drops appreciably.
- Suppose now that the circuit transmits at 1MHz. Suppose also that your radio is tuned to a frequency just below this. The 1MHz transmission will therefore not be heard by the radio. But bring a hand or a foot near to the sensor, and the transmitters frequency will drop, and a beep will be heard from the radio.
- Attach the antenna to a multiplug adapter that is plugged into the mains, and you will find that the Medium Wave transmission radiates from every wire in your house. Now place a suitably tuned Medium Wave radio near some wires or a plug point in your house, and an early-warning system is set up.
- Instead of using the sheet of tin foil as the sensor, you could use a doorknob, or burglar bars. Or you could use a pushbutton and series resistor (wired in series with the 33K resistor - the pushbutton would short it out) to decrease the frequency of IC1a, so activating the system by means of a pushbutton switch. In this case, the radio would be tuned to a frequency just below that of the transmitter.
Tuesday, April 2, 2013
Car Radio Audio Amplifier using TDA2003
The TDA 2003 IC has improved performance with the same pin configuration as the TDA 2002. The additional features of TDA 2002, very low number of external components, ease of assembly, space and cost saving, are maintained. The device provides a high output current capability (up to 3.5A) very low harmonic and cross-over distortion. Completely safe operation is guaranteed due to protection against DC and AC short circuit between all pins and ground, thermal over-range, load dump voltage surge up to 40V and fortuitous open ground.
TDA2003 has DC Characteristic with VDC power supply min 8V and max 18V. If the supply voltage peaks to more than 40V, then an LC filter must be inserted between the supply and pin 5, in order to assure that the pulses at pin 5 will be held within the limits. In short circuit AC and DC conditions, The TDA 2003 can withstand a permanent short circuit on the output for a supply voltage up to 16V. When the radio is in the ON condition and the ground is accidentally opened, a standard audio amplifier will be damaged. On the TDA 2003 protection diodes are included to avoid any damage.
The presence of a thermal limiting circuit offers the following advantages; an overload on the output (even if it is permanent), excessive ambient temperature can be easily withstood. The heat-sink can have a smaller factor compared with that of a conventional circuit. There is no device damage in the case of excessive junction temperature: all that happens is that Po (and there fore P total) and Id are reduced.
TDA2003 has DC Characteristic with VDC power supply min 8V and max 18V. If the supply voltage peaks to more than 40V, then an LC filter must be inserted between the supply and pin 5, in order to assure that the pulses at pin 5 will be held within the limits. In short circuit AC and DC conditions, The TDA 2003 can withstand a permanent short circuit on the output for a supply voltage up to 16V. When the radio is in the ON condition and the ground is accidentally opened, a standard audio amplifier will be damaged. On the TDA 2003 protection diodes are included to avoid any damage.
The presence of a thermal limiting circuit offers the following advantages; an overload on the output (even if it is permanent), excessive ambient temperature can be easily withstood. The heat-sink can have a smaller factor compared with that of a conventional circuit. There is no device damage in the case of excessive junction temperature: all that happens is that Po (and there fore P total) and Id are reduced.
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