GSM Controlled Robot
In the project the robot is controlled by a mobile phone that makes a call to the mobile phone attached to the robot. In the course of a call, if any button is pressed a tone corresponding to the button pressed is heard at the other end called ‘Dual Tone Multiple frequency’ (DTMF) tone.
8x8 Dotmatrix Scrolling LED Display
Here 64 leds which are connected to an Matrix display. The Anodes are drived through an Driver IC UDN2981 and the cathodes are drived through ULN2803. The Atmega8515 is used in this project to control the display. The microcontroller is programmed with Bascom AVR.
50 Watt Amplifier Circuit
This is a handy, easy to build general purpose 50 watt amp. The amp has an input for a radio, TV, stereo or other line level device. It also has a phono input for a record player, guitar, microphone or other un-amplified source. With the addition of a low pass filter at the input, it makes a great amp for a small subwoofer.
Parts List-
R1 - 1 - 200 Ohm 1/4 W Resistor
R2 - 1 - 200K 1/4 W Resistor
R3 - 1 - 30K 1/4 W Resistor
R5 - 1 - 1K 1/4 W Resistor
R6 - 1 - 5K 1/4 W Resistor
R7,R10 - 2 - 1 Meg (5%) 1/2 W Resistor
R8,R9 - 2 - 0.4 Ohm 5 W Resistor
R11 - 1 - 10K Pot
R12,R13 - 2 - 51K 1/4 W Resistor
R14 - 1 - 47K 1/4 W Resistor
C1 - 1 - 100uF 35V Electrolytic Capacitor
C2 - 1 - 0.011uF Capacitor
C3 - 1 - 3750pF Capacitor
C4,C6 - 2 - 1000pF Capacitor
C5,C7,C8 - 3 - 0.001uF Capacitor
C9 - 1 - 50pF Capacitor
C10 - 1 - 0.3uF Capacitor
C11,C12 - 2 - 10,000uF 50V Electrolytic Capacitor
U1,U2 - 2 - 741 Op Amp
U3 - 1 - ICL8063 Audio Amp Transister Driver thingy
Q1 - 1 - 2N3055 NPN Power Transistor
Q2 - 1 - 2N3791 PNP Power Transistor
BR1 - 1 - 250 V 6 Amp Bridge Rectifier
T1 - 1 - 50V Center Tapped 5 Amp Transformer
S1 - 1 - SPST 3 Amp Switch
S2 - 1 - DPDT Switch
F1 - 1 - 2 Amp Fuse
SPKR1 - 1 - 8 Ohm 50W Speaker
MISC - 1 - Case, Knobs, Line Cord, Binding Posts Or Phono Plugs (For Input And Output), Heatsinks For Q1 And Q2
Notes-
1. I know I skipped R4. That is not a problem :-)
2. Distortion is less than 0.1% up to 100HZ and increases to about 1% at 20kHz.
3. I haven't been able to find anyone who sells a suitable T1. You can always use two 24V 5A units in series. If you are building two amps (for stereo), then I would suggest using an old microwave transformer and rewinding it. Follow the instructions in the 12V To 120V Inverter, execpt wind 26 turns, twist a loop (center tap) and wind 26 more turns. That should work out to around 50 volts. You may need to add or remove turns depending on your transformer.
4. Q1 and Q2 will require heatsinks.
Parts List-
R1 - 1 - 200 Ohm 1/4 W Resistor
R2 - 1 - 200K 1/4 W Resistor
R3 - 1 - 30K 1/4 W Resistor
R5 - 1 - 1K 1/4 W Resistor
R6 - 1 - 5K 1/4 W Resistor
R7,R10 - 2 - 1 Meg (5%) 1/2 W Resistor
R8,R9 - 2 - 0.4 Ohm 5 W Resistor
R11 - 1 - 10K Pot
R12,R13 - 2 - 51K 1/4 W Resistor
R14 - 1 - 47K 1/4 W Resistor
C1 - 1 - 100uF 35V Electrolytic Capacitor
C2 - 1 - 0.011uF Capacitor
C3 - 1 - 3750pF Capacitor
C4,C6 - 2 - 1000pF Capacitor
C5,C7,C8 - 3 - 0.001uF Capacitor
C9 - 1 - 50pF Capacitor
C10 - 1 - 0.3uF Capacitor
C11,C12 - 2 - 10,000uF 50V Electrolytic Capacitor
U1,U2 - 2 - 741 Op Amp
U3 - 1 - ICL8063 Audio Amp Transister Driver thingy
Q1 - 1 - 2N3055 NPN Power Transistor
Q2 - 1 - 2N3791 PNP Power Transistor
BR1 - 1 - 250 V 6 Amp Bridge Rectifier
T1 - 1 - 50V Center Tapped 5 Amp Transformer
S1 - 1 - SPST 3 Amp Switch
S2 - 1 - DPDT Switch
F1 - 1 - 2 Amp Fuse
SPKR1 - 1 - 8 Ohm 50W Speaker
MISC - 1 - Case, Knobs, Line Cord, Binding Posts Or Phono Plugs (For Input And Output), Heatsinks For Q1 And Q2
Notes-
1. I know I skipped R4. That is not a problem :-)
2. Distortion is less than 0.1% up to 100HZ and increases to about 1% at 20kHz.
3. I haven't been able to find anyone who sells a suitable T1. You can always use two 24V 5A units in series. If you are building two amps (for stereo), then I would suggest using an old microwave transformer and rewinding it. Follow the instructions in the 12V To 120V Inverter, execpt wind 26 turns, twist a loop (center tap) and wind 26 more turns. That should work out to around 50 volts. You may need to add or remove turns depending on your transformer.
4. Q1 and Q2 will require heatsinks.
Transformerless Power Supply
Parts List-
C1 - 1 - 0.39uF 250V Capacitor
C2 - 1 - 220uF 25V Electrolytic Capacitor
D1 - 1 - 1N4741 11V Zener Diode (See Notes)
BR1 - 1 - 1 Amp 200V Bridge Rectifier
MISC - 1 - Line Cord, Board, Wire, Case
Notes-
1. The value of C1 can be increased to increase the amount of current the circuit can supply. With the values shown, the circuit can supply up to about 15mA. Remember to increase the size of C2 also.
2. <>A different value can be used for D1 to increase or decrease the voltage as needed.
3. Please note that this circuit is not isolated from 120VAC. Because of this, the circuit must be treated with caution and encosed at all times. Do not work on the circuit (or any other circuits attached to it) when it is plugged in.
4. You may want to add a resisor in series with C1 to limit current if the circuit is plugged in and the mains is at its full voltage.
5. If you are running the circuit from 220VAC, then use a capacitor rated at greater than 400V for C1.
6. If you want isolation from the AC line, you can connect up a small isolation transformer at the inputs of the circuit. Small 600ohm:600ohm audio transformers work nicely.
Fixed Voltage Power Supply
Parts List-
C1 - 1 - 2200uF 35V Electrolytic Capacitor
C2, C4 - 2 - 0.1uF Ceramic Disc Capacitor
C3 - 1 - 10uF 35V Electrolytic Capacitor
D1, D2 - 2 - 1N4007 Silicon Diode
BR1 - 1 - 2A 30V Bridge Rectifier
U1 - 1 - Regulator (See Notes)
T1 - 1 - Transformer (See Notes)
S1 - 1 - SPST 2 Amp Switch
F1 - 1 - 2A 250V Fuse and Holder
MISC - 1 - Heatsink For U1, Line Cord, Case, Wire
Notes-
1. Since this project operates from 120 (or 220, or 240, etc.) volts AC, it MUST be built inside a case.
2. U1 will reauire a heatsink.
3. You will need to choose T1 and U1 to match the voltage you want. Use the table below as a reference.
Output Voltage
T1U1
5V 6V, 1.5A 7805
6V 6V, 1.5A 7806
9V 12V, 1.5A 7809
12V 12V, 1.5A 7812
15V 24V, 1.5A 7815
18V 24V, 1.5A 7818
Laser Power Supply
Parts List-
R1 - 1 - 10 Ohm 10W Or Greater Resistor
R2 - 1 - Ballast Resistor, See "Notes"
D1, D2, D3 - 3 - 1N4007 Silicon Diode
C1, C2, C3 - 3 - 0.1 uF 2000V Capacitor
T1 - 1 - 9V 1A Transformer
S1 - 1 - 115V 2A SPST Switch
MISC - 1 - Case, Wire, Binding Posts (for output), Line Cord
Notes-
1. T1 is an ordinary 9V 1A transformer connected backwards for step up.
2. R1 MUST be installed on a LARGE heatsink. A good heatsink is the metal case the supply is built in.
3. R2 Protects the laser tube from excess current. It should be soldered directly to the anode terminal on the tube. To find R2, start with a 500K 10W resistor and work down until the tube lights and remains stable.
4. If you have trouble with the tube not starting easily, use a longer anode lead that is wrapped around the tube.
5. Depending on the transformer you use, the circuit may or may not work. I cannot guarantee the operation of this circuit. Build at your own risk. Some transformers contain very few secondary windings which will quickly saturate the core and basically act like a direct short. The more secondary windings (that is, primary in this circuit) the better.
Clap Switch Circuit
The transformer is 220V to 15V -0V-15V transformer of a minimum of 10VA. You can replace the 1N4001 diodes of any types with similar ratings.The relay is 12V with 5A output current capacity or higher. You can replace also the transistor of any general purpose type.
Note: This clap activated relay is connected to main supply (220VAC). Do not try to touch the main supply to avoid electrocution or do not try to construct if you do not have any idea in electronics.
Led emergency light using cellphone battery and charger
Emergency lighting system uses LED and powered by a 3.6V cellphone battery or any battery of the same voltage. The battery is charge by a cellphone charger with a current of 350mA. During the
charging process, transistor Q1 is off so are the LEDs. When the power is cutoff (brownout), transistor is energized an delivers 25mA current to the four LED. The emergency light consumes about 0.5W and a fully charge battery can last up to 5hours.
Parts List
D2, D3, D4, D5- preferably white LEDs
Q1- 9012 or any general purpose pnp transistor
cellphone battery or similar
Battery charger
1000uF /10V capacitor
4.7k and 220 ohms 0.25W resistor
5 ohms 1W resistor
Simple LED Emergency Light Circuit
Emergency light project is simple, cheap and easy to build. The circuit do the charging of the battery and when the main source is not available such as in brownouts, the white LEDs
automatically turn on.
Initially, the voltage output from 220V to 12V converter is fed to the input of LM317 regulator. Then this voltage is regulated down to 7.37V using 240 ohms and 1.2K resistor combination (see LM317 Calculator). At this instant, the battery is in charging mode and the transistor Q1 is off. Indicator LED serves two purpose, one primarily is to give us idea
that the battery is charging and another is to ensure that the Q1 is off. During brownouts, the transistor Q1 is on and delivers current to 16 white LED of about 20mA each, thus a fully charged battery (6V/4.5Ah) can last up to 14 hours.
The charger has no built in over-current control but still it protects the battery from overcharging since the charging voltage is set only to 7.4V.
Project materials:
1pc - transformer - 220V to 12V-0-12V , center tap 12VA
16pc - 120 ohms resistor 1/4 W
16pc - white LED min 3V@30mA
1pc - red LED
1pc - 1000uF/25V electrolytic capacitor
3pc - 1N4001 diode
1pc - LM317 regulator
1pc - 1.5K resistor 1/4W
1pc - 240 ohms resistor 1/4W
1pc - 1.2k resistor 1/4W
1pc - 9012 pnp transistor or any of much higher capacity
1pc - 6V 4.5ah battery
6V to 12V dc-dc boost converter by 555 timer
This 6V to 12V dc-dc boost converter can drive a load in 12V about 3A current.The 555 timer IC is operated in astable mode, generates about 29Khz frequency of about 54% duty cycle drives the input of TIP41C transistor.1000uF capacitor smoothens the output voltage of the dc-dc converter.LED and 1.5Kohm resistor serves as indicator and load for output stability when no load is connected.You can add a 12V zener diode (1N5242B)across output to ground for further output stability.
The 39ohm resistor at the base of transistor is rated 1W, the rest 1/4W or more.Inductor can be made out of #22AWG wire wound around on an old transistor radio ferrite core.Number of turns more than 30T, but not critical.Change the values and experiment more using this circuit.
12V to 5V DC converter using 7805 regulator IC
This simple converter project uses 7805 IC to convert 12V dc from a battery to 5V DC. This converter also can be made even only one component, the 7805 regulator. Converter can produce a maximum current of 1.5A (with heatsink) at 5V from an input of 8V to 15V. The capacitors are optional and can be omitted.
This is suitable for powering devices that uses 5V DC such as chargers,USB devices and others
3V Electronic Stun Gun Circuit
Schematic-
This circuit above is a cheap version stun gun circuit that is powered by two AA baterry. The output of this electronic project is about 350V dc.
The heart of the circuit is the oscillator that is composed of Windings and transistor.
Primary winding P is composed of 16 turns of #24 AWG wire, feedback F is composed of 8 turns of #24 AWG wire, and secondary winding S is composed of 270 turns of #30 AWG magnetic wire. The output of Sec winding is rectified by diode bridge. The output capacitor is an electrolytic type that is rated 400V above. Capacitance of the output capacitor depends on what available on hand,but always keep in mind that the higher the value the better. this simple electronic project is dangerous when accidentally touched, thus avoid holding the output and discharge the capacitor before and after using.
This circuit above is a cheap version stun gun circuit that is powered by two AA baterry. The output of this electronic project is about 350V dc.
The heart of the circuit is the oscillator that is composed of Windings and transistor.
Primary winding P is composed of 16 turns of #24 AWG wire, feedback F is composed of 8 turns of #24 AWG wire, and secondary winding S is composed of 270 turns of #30 AWG magnetic wire. The output of Sec winding is rectified by diode bridge. The output capacitor is an electrolytic type that is rated 400V above. Capacitance of the output capacitor depends on what available on hand,but always keep in mind that the higher the value the better. this simple electronic project is dangerous when accidentally touched, thus avoid holding the output and discharge the capacitor before and after using.
220V led lamp (AC powered LED)
220V led lamp (AC powered LED)
Schematic-
This LED lamp is powered by an ac source available in your outlet.
To build this LED lamp you will need 20 white LED and capacitor.
the Lamp consumes about 4w of power.
Note:
Capacitor C1 is mylar type and do not use electrolytic capacitor. Avoid touching any part of the circuit
since it is powered directly to the main ac source.
Capacitor of this LED lamp is as follows:
220nF if ac line is 220V @ 60Hz
270nF if ac line is 220V @ 50Hz
470nF if ac line is 110V @ 60Hz
578nF if ac line is 110V @ 60Hz
Schematic-
This LED lamp is powered by an ac source available in your outlet.
To build this LED lamp you will need 20 white LED and capacitor.
the Lamp consumes about 4w of power.
Note:
Capacitor C1 is mylar type and do not use electrolytic capacitor. Avoid touching any part of the circuit
since it is powered directly to the main ac source.
Capacitor of this LED lamp is as follows:
220nF if ac line is 220V @ 60Hz
270nF if ac line is 220V @ 50Hz
470nF if ac line is 110V @ 60Hz
578nF if ac line is 110V @ 60Hz
22 Watt Audio Amplifier Circuit
The 22 watt amp is easy to build, and very inexpensive. The circuit can be used as a booster in a car audio system, an amp for satellite speakers in a surround sound or home theater system, or as an amp for computer speakers. The circuit is quite compact and uses only about 60 watts.
Schematic-
Parts List-
R1 - 1 - 39K 1/4 Watt Resistor
C1,C2 - 2 - 10uf 25V Electrolytic Capacitor
C3 - 1 - 100uf 25V Electrolytic Capacitor
C4 - 1 - 47uf 25V Electrolytic Capacitor
C5 - 1 - 0.1uf 25V Ceramic Capacitor
C6 - 1 - 2200uf 25V Electrolytic Capacitor
U1 - 1 - TDA1554 Two Channel Audio Amp Chip
MISC - 1 - Heatsink For U1, Binding Posts (For Output), RCA Jacks (For Input), Wire, Board
Notes-
1) The circuit works best with 4 ohm speakers, but 8 ohm units will do.
2) The circuit dissipates roughly 28 watts of heat, so a good heatsink is necessary. The chip should run cool enough to touch with the proper heatsink installed.
3) The circuit operates at 12 Volts at about 5 Amps at full volume. Lower volumes use less current, and therefore produce less heat.
4) Printed circuit board is preferred, but universal solder or perf board will do. Keep lead length short.
Schematic-
Parts List-
R1 - 1 - 39K 1/4 Watt Resistor
C1,C2 - 2 - 10uf 25V Electrolytic Capacitor
C3 - 1 - 100uf 25V Electrolytic Capacitor
C4 - 1 - 47uf 25V Electrolytic Capacitor
C5 - 1 - 0.1uf 25V Ceramic Capacitor
C6 - 1 - 2200uf 25V Electrolytic Capacitor
U1 - 1 - TDA1554 Two Channel Audio Amp Chip
MISC - 1 - Heatsink For U1, Binding Posts (For Output), RCA Jacks (For Input), Wire, Board
Notes-
1) The circuit works best with 4 ohm speakers, but 8 ohm units will do.
2) The circuit dissipates roughly 28 watts of heat, so a good heatsink is necessary. The chip should run cool enough to touch with the proper heatsink installed.
3) The circuit operates at 12 Volts at about 5 Amps at full volume. Lower volumes use less current, and therefore produce less heat.
4) Printed circuit board is preferred, but universal solder or perf board will do. Keep lead length short.
Voltage Inverter Circuit
This simple and inexpensive circuit can produce a dual (positive and negative) voltage from a single supply input. It is therefore extremely useful for powering opamp and other circuits that require a dual voltage from a single battery. The circuit will operate at an input voltage from around 5V to 20V and produce a output from +-2.5V to +-10V.
Schematic-
Parts List-
R1 - 1 - 1M Linear Pot
C1,C2 - 2 - 15uf 25V Electrolytic Capacitor
U1 - 1 - LM380 Audio Amp Chip
MISC - 1 - Heatsink For U1, Binding Posts (For Input/Output), Wire, Board
Notes -
1) U1 dissipates around 1W and will therefore require a heatsink.
2) R1 is used to equalize the outputs. The first time you use the circuit, it should be set to mid range and then adjusted with the aid of a voltmeter. Measure each output while adjusting. The circuit is calibrated when both outputs read the same voltage (either positive or negative).
Schematic-
Parts List-
R1 - 1 - 1M Linear Pot
C1,C2 - 2 - 15uf 25V Electrolytic Capacitor
U1 - 1 - LM380 Audio Amp Chip
MISC - 1 - Heatsink For U1, Binding Posts (For Input/Output), Wire, Board
Notes -
1) U1 dissipates around 1W and will therefore require a heatsink.
2) R1 is used to equalize the outputs. The first time you use the circuit, it should be set to mid range and then adjusted with the aid of a voltmeter. Measure each output while adjusting. The circuit is calibrated when both outputs read the same voltage (either positive or negative).
Computer Controlled Frequency Counter/Logic Probe Circuit
This circuit is a stable frequency counter accurate to 5 significant digits. The range is 0 - 30MHz with an input sensitivity of greater then 100mV. The probe connects to the PC serial port. So by using the crystal oscillator already present on your PC serial card and software calibration, the Probes' external circuitry is kept to a minimum. Probe 9 can also be used as a logic probe/analyzer using included software (LPROBE92.EXE).
Schematic-
Parts List-
R1,R2,R3,R4 - 4 - 100K 1/4W Resistor
R5 - 1 - 10M 1/4W Resistor
R6, R7 - 2 - 3.3K 1/4W Resistor
R8 - 1 - 390 Ohm 1/4W Resistor
R9 - 1 - 1M 1/4W Resistor
C1, C4 - 2 - 0.1uF Ceramic Disc Capacitor
C2, C3 - 2 - 100uF 16V Electrolytic Capacitor
D1 - 1 - 1N4148 Signal Diode or Any 200mA silicon signal diode
D2, D3 - 2 - 3.3V Zener Diode
D4 - 1 - 6.2V Zener Diode
U1 - 1 - 74HC00 Quad Highspeed NAND Gate
U2, U3, U4 - 3 - 4021 8 Stage Shift Register
U5 - 1 - 74HC393 Dual Highspeed 4 Bit Counter
U6 - 1 - 4040 12 Stage Binary Counter
MISC - 1 - PC Board, Wire, Suitable Probe, DB9/DB25 Connector
Notes-
1) The software to use this probe can be downloaded using the following link. Note that this software is compiled for Intel x86 platforms and runs under DOS, Win95, Win98 and WinMe. It does not run under any Windows version based on NT including Windows NT 3.51, WinNT4, Win2K, Win2K3, WinXP and Windows Vista. This is because NT based operating systems do not allow direct hardware access.
Download Probe Software, Zipped, 19K
2) SETPROBE.EXE is the frequency counter calibration program. To give accurate readings the Probe must be calibrated to your PC. SETPROBE.EXE calculates the constant error correction factor for the particular PC serial card the probe is to be used on. The frequency counter corrects for this slight constant error in crystal frequency by using the correction factor contained in PROBE.DAT. To calculate this correction factor, a reliable oscillator of known frequency (eg 2MHz Crystal Oscillator) is required. When CALIBRAT.EXE is run, the Probe will sample the frequency and then ask for the true frequency value in HZ. The frequency entered must be to 1 Hz accuracy (no decimal points) or an error will occur (for example "200123" not "200123.34" or "2003.421 kHz"). The program then calculates constant error correction factor and stores it to PROBE.DAT. Calibration is only necessary once.
3) LPROBE92.EXE is the logic analysis program . Logic states are displayed in real time. This program runs best under DOS (not a DOS window). The sampling speed is adjusted by using the left and right arrow keys.
The three triggering modes are:
* TRIG: Starts each scan (left-right of screen) on a negative going edge of logic signal.
* KEY TRIG: Waits for a key to be pressed before beginning each scan.
* FREE RUNNING: Not triggered.
To Toggle between these use the UP / DOWN arrow keys. To quit from LPROBE press escape.
4) FPROBE92.EXE is the frequency counter program. The measured frequency is displayed in Hz with commas indicating KHz and MHz. To quit from FPROBE press any key.
5) Serial port pinouts are as follows.
9pin - 25 pin
TD - 3 - 2
RTS - 7 - 4
DTR - 4 - 20
DSR - 6 - 6
CTS - 8 - 5
SG 5 7
Schematic-
Parts List-
R1,R2,R3,R4 - 4 - 100K 1/4W Resistor
R5 - 1 - 10M 1/4W Resistor
R6, R7 - 2 - 3.3K 1/4W Resistor
R8 - 1 - 390 Ohm 1/4W Resistor
R9 - 1 - 1M 1/4W Resistor
C1, C4 - 2 - 0.1uF Ceramic Disc Capacitor
C2, C3 - 2 - 100uF 16V Electrolytic Capacitor
D1 - 1 - 1N4148 Signal Diode or Any 200mA silicon signal diode
D2, D3 - 2 - 3.3V Zener Diode
D4 - 1 - 6.2V Zener Diode
U1 - 1 - 74HC00 Quad Highspeed NAND Gate
U2, U3, U4 - 3 - 4021 8 Stage Shift Register
U5 - 1 - 74HC393 Dual Highspeed 4 Bit Counter
U6 - 1 - 4040 12 Stage Binary Counter
MISC - 1 - PC Board, Wire, Suitable Probe, DB9/DB25 Connector
Notes-
1) The software to use this probe can be downloaded using the following link. Note that this software is compiled for Intel x86 platforms and runs under DOS, Win95, Win98 and WinMe. It does not run under any Windows version based on NT including Windows NT 3.51, WinNT4, Win2K, Win2K3, WinXP and Windows Vista. This is because NT based operating systems do not allow direct hardware access.
Download Probe Software, Zipped, 19K
2) SETPROBE.EXE is the frequency counter calibration program. To give accurate readings the Probe must be calibrated to your PC. SETPROBE.EXE calculates the constant error correction factor for the particular PC serial card the probe is to be used on. The frequency counter corrects for this slight constant error in crystal frequency by using the correction factor contained in PROBE.DAT. To calculate this correction factor, a reliable oscillator of known frequency (eg 2MHz Crystal Oscillator) is required. When CALIBRAT.EXE is run, the Probe will sample the frequency and then ask for the true frequency value in HZ. The frequency entered must be to 1 Hz accuracy (no decimal points) or an error will occur (for example "200123" not "200123.34" or "2003.421 kHz"). The program then calculates constant error correction factor and stores it to PROBE.DAT. Calibration is only necessary once.
3) LPROBE92.EXE is the logic analysis program . Logic states are displayed in real time. This program runs best under DOS (not a DOS window). The sampling speed is adjusted by using the left and right arrow keys.
The three triggering modes are:
* TRIG: Starts each scan (left-right of screen) on a negative going edge of logic signal.
* KEY TRIG: Waits for a key to be pressed before beginning each scan.
* FREE RUNNING: Not triggered.
To Toggle between these use the UP / DOWN arrow keys. To quit from LPROBE press escape.
4) FPROBE92.EXE is the frequency counter program. The measured frequency is displayed in Hz with commas indicating KHz and MHz. To quit from FPROBE press any key.
5) Serial port pinouts are as follows.
9pin - 25 pin
TD - 3 - 2
RTS - 7 - 4
DTR - 4 - 20
DSR - 6 - 6
CTS - 8 - 5
SG 5 7
Car Alarm Arming Horn Beep Canceller Circuit
It's a great convenience that most modern cars come with a built in alarm, however it is nothing but noise pollution that the horn sounds when the alarm is armed. Disconnecting the alarm system from the horn relay will eliminate this, but prevent the horn from sounding in the even of an actual alarm. This circuit serves to silence the arming beep yet maintain the alarm by introducing a small delay into the signal. It sits between the alarm and horn relay. The alarm must provide a constant horn signal for at least 3 seconds before the horn relay is activated. That way the quick "beep" will never activate the horn relay, while the constant alarm signal will.
Schematic-
Parts List-
C1 - 1 - 0.01uF Ceramic Disc Capacitor
C2 - 1 - 100uF 35V Electrolytic Capacitor
R1 - 1 - 1K 1/4W Resistor
R2 - 1 - 10K 1/4W Resistor
R3 - 1 - 15K 1/4W Resistor
R4 - 1 - 470 Ohm 1/4W Resistor
D1, D3, D4 - 3 - 1N4004 Rectifier Diode
D2 - 1 - Red LED
U1 - 1 - 555 Timer IC
K1 - 1 - SPST 12V Automotive Relay
MISC - 1 - Board, Wire, Socket For U1, Case
Schematic-
Parts List-
C1 - 1 - 0.01uF Ceramic Disc Capacitor
C2 - 1 - 100uF 35V Electrolytic Capacitor
R1 - 1 - 1K 1/4W Resistor
R2 - 1 - 10K 1/4W Resistor
R3 - 1 - 15K 1/4W Resistor
R4 - 1 - 470 Ohm 1/4W Resistor
D1, D3, D4 - 3 - 1N4004 Rectifier Diode
D2 - 1 - Red LED
U1 - 1 - 555 Timer IC
K1 - 1 - SPST 12V Automotive Relay
MISC - 1 - Board, Wire, Socket For U1, Case
