วันศุกร์ที่ 8 ตุลาคม พ.ศ. 2553
Time Delay Relay Circuit
C1 10uf 16V Electrolytic CapacitorC2 0.01uf Ceramic Disc Capacitor
R1 1 Meg Pot
R2 10 K 1/4 Watt Resistor
D1,D2 1N914 Diodes
U1 555 Timer IC
RELAY 9V Relay
S1 Normally Open Push Button Switch
Notes:
1. R1 adjusts the on time.
2. You can use a different capacitor for C1 to change the maximum on time.
3. S1 is used to activate the timing cycle. S1 can be replaced by a NPN transistor so that the circuit may be triggered by a computer, other circuit, etc.
step-down converter (MC34063A) Circuit
The step down converter is the power unit to make the output voltage which is lower than the input voltage. The converter which was made this time makes +2V to +10V output voltage with the input voltage of +12V. Because it makes the limitation value of the input electric current about 1.3A, the maximum with the input electric power is about 16W.
Ignition Coil Buzz Box
Here's a circuit to create a buzzcoil using a standard automotive ignition coil. A 556 dual timer is used to establish the frequency and duty cycle of the coil current. One of the timers is used as an oscillator to generate the 200 Hz rectangular waveform needed to control the (IRF740 MOSFET) while the second timer switches the oscillator on and off as the breaker points open and close (closed = on). The result is a steady stream of sparks from the ignition coil spaced about 5 milliseconds apart while the breaker points are closed. Operation: Pin 8 and 12 are the threshold and trigger inputs of one timer which are driven by the breaker points and produce an inverted signal at the timer output (pin 9). When the points are closed to ground, pin 9 will be high and visa versa. The signal at pin 9 controls the reset line (pin 4) of the second timer and holds the output at pin 5 low while pin 4 is low and pins 8 and 12 are high (points open). The 15K and 4.7K resistors and 0.33uF capacitor are the timing components that establish the frequecy and duty cycle of the second timer which is about 4 milliseconds for the positive interval and 2 milliseconds for the negative. During the positive time interval, the MOSFET gates are held high which causes the ignition coil current to rise to about 4 amps. This equates to about 80 millijoules of energy in the coil which is released into the spark plug when the timer output (pin 5) moves to ground, turning off the MOSFET. A 12 volt zener diode is placed at the junction of the 10 and 27 ohm resistors to insure the MOSFET gate input never goes above 12 volts or lower than -0.7 volts. A 200 volt/5 watt zener is used at the MOSFET drain to limit the voltage to +200 and lengthen the spark duration. The circuit should operate reliably with a shorted plug, however operating the circuit with no load connected (plug wires fallen off, etc.) may cause a failure due to most of the power being absorbed by the zener. You can also use a transient voltage suppressor (TVS) such as the 1.5KE200A or 1.5KE300A in place of the zener. It's probably a better part, but hard to obtain
Electric power controller Circuit
The equipment which can be controlled The equipment which works by the resistance. Such as the the tungsten-filament lamp, the soldering iron and so on. The equipment which is using the AC series motor(with the brush). Such as the drill, the electric fan, the cleaner and so on. The equipment which can not do the control The fluorescence light. The synchronous motor(using the capacitor) As for the synchronous motor, the number of rotations is decided by the frequency of the alternating current. So, basically, it isn't possible to control with the circuit this time. However, the torque(power to turn) of the motor declines when the electric current which flows through the synchronous motor decreases. With it, the revolution can be slowed down. In this case, with the load which is applied to the axis of the motor, the number of rotations isn't constant. The electric power which can be controlled is decided by the permission value of the electric current which can pour into the TRIAC. I used the TRIAC which can apply the 12-A electric current to the circuit this time. In the calculation, in case of AC 100V, a maximum of 1200 W can be controlled but in the actual use, about 700 W or 800 W are safe.
Alternating ON-OFF Switch Circuit
R1 = 10K R2 = 100K
R3 = 10K
R4 = 220 Ohm (optional)
C1 = 0.1µF, Ceramic (100nF)
C2 = 1µF/16V, Electrolytic
D1 = 1N4001
Led1 = Led, 3mm, red (optional)
Q1 = 2N4401 (see text) IC1 = 4069, CMOS, Hex Inverter (MC14069UB), or equivalent
S1 = Momentary on-switch
Ry1 = Relay )
Air Flow Detector Circuit
R1 100 Ohm 1/4W Resistor R2 470 Ohm 1/4W Resistor
R3 10k 1/4W Resistor
R4 100K 1/4W Resistor
R5 1K 1/4W Resistor
C1 47uF Electrolytic Capacitor
U1 78L05 Voltage Regulator
U2 LM339 Op Amp
L1 #47 Incandescent lamp with glass removed (See "Notes")
D1 LED
Notes:
1. The glass will have to be removed from L1 without breaking the filament. Wrap the glass in masking tape and it in a vise. Slowly crank down until the glass breaks, then remove the bulb and carefully peel back the tape. If the filament has broken, you will need another lamp.
8 Relay Control
R1-8=4.7 Kohms T1-8= BD139 (R1-8=15 Kohms if T1-8=BD679) RL1-8=6V-24V dc Relay D1-8=1N4148
วันจันทร์ที่ 4 ตุลาคม พ.ศ. 2553
Zener Oscillators Circuit
These two circuits are interesting from an academic point of view. Their practical implementation is rather critical and it is not easy to get steady operation. Circuit (a) requires a "cooked" zener: connect it first to a constant current generator, then increase the current until the voltage across the zener starts to decrease. Reduce the supply current and wait a few minutes until it really warms up. The zener is now ready for the circuit: increase the voltage slowly until it oscillates (1KHz in the circuit shown). You may need to decrease the voltage once oscillation takes place. With suitable circuit components it will oscillate up to 20MHz. Circuit (b) will oscillate at a very low frequency, normally 2-5Hz, provided the voltage is increased very slowly, loading is critical and you may find that a slightly different lamp will work better. Higher voltage zeners work better than low voltage zeners and the circuits operate only with the specified types. The reasons for the oscillations are unknown, although, for circuit (b) it is felt that some kind of reversible thermal breakdown is at work.
Wireless Auto Tachometer
C1 1 0.47uF CapacitorC2 47uF Electrolytic Capacitor
D1 8V 1W Zener Diode
D2, D3, D4 1N914 Diode
M1 200uA Meter
Q1, Q2 2N3391A Transistor
R1, R2, R9 1K 1/2 W Resistor
R3 47K 1/2 W Resistor
R4 10K 1/2 W Resistor
R5, R6 25K Trim Pot
R7 10K Trim Pot
R8 200 Ohm 2 W Resistor
R1 15K 1/2 W Resistor
R1 2.2K 1/2 W Resistor
S1 SPST Togglae Switch
S2 Three Position Single Pole Rotary Switch
Notes:
1. Calibrate the unit as folows:
a. Set up this circuit:
b. Turn on the Tach and allow a few minutes for temperature stabilization.
c. Set S2 to 4 cylinders and adjust R5 for a meter indication of 180 (1800 rpm).
d. Set S2 to 6 cylinders and adjust R6 for a meter indication of 120 (1200 rpm).
e. Set S2 to 8 cylinders and adjust R7 for a meter indication of 90 (900 rpm).
2. To use the Tach, turn it on and let it sit for one minute to allow for temperature stabilization. Extend the antenna, select the right number of cylinders and hold the unit over the engine. If the reading is erratic or the needle jumps around, move the antenna closer to the ignition coil or spark plug wires.
3. The unit draws power from the car battery. If it is connected backwards, it will not work, but it won't be damaged.
Wire Loop Alarm
R1 100K 1/2W 1% Resistor
R2, R4 10K 1/2W 1% Resistor
R3 1 Meg 1/2W 1% Resistor
C1, C3 0.1uF Ceramic Disc Capacitor
C2 0.01uF Ceramic Disc Capacitor
IC1 4001UBE Quad 2-i/p NOR Gate
Q1 MPSA14 Low Power NPN Transistor
SIREN Micro piezo siren 12V DC 150mA, 110dB @ 1M
LOOP See "Notes"
The loop can be any type of hookup wire, with a maximum resistance of about 90K. Using very thin wire (40AWG, for example) will make a very sensitive trip wire, but will shorten the distance it can be strung due to the high resistance.
The siren can be replaced with a relay to drive external loads.
Video Activated Relay
input = video inputR1, R2 10K 1/4 W Resistor
R3 1K 1/4 W Resistor
R4 33K 1/4 W Resistor
C1 1uF Electrolytic Capacitor
Q1, Q2, Q3 2N2222 NPN Transistor 2N3904 NPN Transistor
D1, D2, D3 1N4148 Diode
K1 9V Relay
J1 RCA Jack
R3 1K 1/4 W Resistor
R4 33K 1/4 W Resistor
C1 1uF Electrolytic Capacitor
Q1, Q2, Q3 2N2222 NPN Transistor 2N3904 NPN Transistor
D1, D2, D3 1N4148 Diode
K1 9V Relay
J1 RCA Jack
Notes:
1. Since you may be using this circuit to switch mains voltage, it should be enclosed in a case.
2. The circuit will also work with most line level audio, although you may have to adjust the value of R1
1. Since you may be using this circuit to switch mains voltage, it should be enclosed in a case.
2. The circuit will also work with most line level audio, although you may have to adjust the value of R1
Ultra Low Frequency Receiver
The frequency covered is from 0.1Hz to 10Hz and useful signals are received up to 16Hz. The first Op-Amp, properly shielded, must be installed close to the antenna (1-3m long) and connected to the rest of the circuit with a 5-core shielded cable. Adjust the 100k trimmer so that the DC setting at the output of the OPA124 does not change when turning the 220k sensitivity pot. A low pass filter followed by a notch filter take care of the mains induced noise. The values in brackets are good for a 60Hz mains. 1% components should be used for the 3 resistors and 3 capacitors of the notch filter. A voltage controlled oscillator gives an audible frequency that follows the input signal and it is very handy if the unit is made portable although I found that just walking around is enough to bury the signal being received. The output signal goes first to a meter and then is available for the connection to a data logger, which is an almost essential part of the receiver. Sensitivity is quite adequate: any TV set switching on in the area will be detected. There are also a host of other mysterious signals of unknown origin. The input protection diodes are special low leakage type and should not be replaced by standard diodes. These diodes can be dispensed with if the antenna is installed with care and away from strong electric fields. The diodes connected to the meter are Schottky diodes and will provide a bias against very small signals (mostly noise) which will not go through to the data logger. Pin connection for OPA124: 1 and 5: DC set, 2 and 3: inverting and non-inverting, 6: output, 8: substrate. Pin connection for LF412: 2 and 3: inverting and non-inverting, 1: output, 6 and 5: inverting and non-inverting, 7: output
