When SI (sensor) is closed, power is applied to U2, a dual timer. After a time determined by C2, CI is ene..
A circuit for multiplying the width of incoming pulses by a factor greater or less than unity is simple to build and has the feature that the multiplying factor can be selected by adjusting one potentiometer only. The multiplying factor is determined by setting the potentiometer in the feedback of a 741 amplifier. The input pulses of width r and repetition period is used to trigger a sawtooth generator at its rising edges to produce the waveform e2 having a peak value of.....
Pulses from the distributor points are passed through a current limiting resistor, rectified, and clipped at 4 volts. Via Q1 and the diode pump, a dc voltage proportional to engine rpm is presented to RV1; the sharp transfer characteristic of a CMOS gate, assisted by feedback, is used to enable the oscillator formed by the remaining half of the 4011..
This relatively simple, inexpensive circuit requiring one trimming operation can multiply or divide with a consistentaccuracy of greater than 1 part in 1,000. An inexpensive CMOS version of standard 555 timer chip T, in conjunction with low-drift LMll error amplifier A3, an inexpensive analog chopper switch SW, form a unique voltage-to-duty-cycle converter to produce the difficult transfer function necessary for accurate conversion. ..
The meltdown is a magnet held to a small stand by ice. A reed switch is below the magnet..
These short-circuit protected regulators give 6, 7, and 9 V from an automobile battery supply of 13 V nominal; however, they will function just as well if connected to a smoothed dc output from a transformer/rectifier circuit. Two types are shown for both positive and negative ground systems. The power transistors can be mounted on the heatsink without a mica insulating spacer thus allowing for greater cooling efficiency. Both circuits are protected against overload or.....
The ramp voltage from the low frequency oscillator 1C1 modulates IC2 thereby producing a rising and falling tone like the siren ..
Output voltage great enough to jump a l-inch gap can be obtained from a 12-V power source. A 555 timer IC is connected as an astable multivibrator that produces a narrow negative pulse at pin 3. The pulse turns Ql on for the duration of the time period. The collector of Ql is direct-coupled to tbe base of tbe power transistor Q2, turning it on during the same time period. ..
This circuit can detect the positive peaks for signal frequencies higher than 5 MHz. It yields ±1% accuracy for 400 mV to 4 V pk-pk signal amplitudes on sine, square, and triangular waveforms. The Am685 comparator output increases whenever VrN is a greater negative voltage than Vour; the high comparator output, in turn, charges C1 in a positive direction. The CA3140 op amp amplifies the C1 voltage with respect to the ECL-switching-threshold voltage ( -1.3 V).....
When the light beam that falls in the CDS photocell is interrupted, transistor (EN3904) conducts thereby triggering SCR1 (CI06) and activating alarm bell. SI resets the SCR. The alarm bell should be a self-interrupting electromechanical type...
This is a cross-sectional diagram of a flex switch. They can be used as pushbutton or even position sensors. This schematic diagram shows an oscillator, which is used as an alarm sounder,..
The base of Ql is connected to the car`s ignition circuit; the easiest point to make that connection is at the ignition switch fuse in the car`s fuse panel. Also, one side of the piezoelectric buzzer is connected to the instrument-panel light fuse; when the headlights or parking lights are on, the instrument panel is lit, too. When the headlights are off, no current reaches the buzzer. Therefore, nothing happens. What happens when the headlights arc on depends on the.....
This is a high quality power supply with a continuously variable stabilized output adjustable between 0 and 30VDC. the LM 723 is the heart of the power supply which drives the BD137 and then the 2N3055. The circuit provides short circuit protection. And has great stability at voltage changes. ..
Two SCRs are used with two sensor loops. One loop uses series switches, the other loop parallel switches. When a switch actuation occurs, the SCR triggers...
IC1 generates a pulse that modulates the 1000-Hz tone generated by IC2...
In machine and equipment design. some applications require measurement of both the shaft speed and the direction of rotation. Fig. 56-4 shows the circuit of a tachometer, which also indicates the direction of rotation. The flywheel has two magnets embedded in the outer rim about 45° apart. One magnet has the north pole toward the outside and the other magnet has the south pole toward the outside rim of the flywheel. ..
This dc supply is great for operating battery-powered antique radios, because it is designed to prevent harming the tube filaments. ..
False alarms produced by semiconductor failure are impossible with this burglar-alarm circuit equipped with relays. What"s more, the circuit is virtually immune to false triggering. With a standby current of less than 0.1 mA, the circuit offers all the features an alarm needs: entry and exit delays, a timed alarm period, and automatic reset after an intrusion. One CMOS CD4093B quad NAND gate, IC1, supplies both logic and analog timing functions with the aid of.....
The tone generated by a 555 oscillator can be turned on (activated) by heat or light. That causes Ql to conduct transistor W2 (TIP 3055)...
When liquid level reaches both probes, alarm is turned on..
Operational Amplifiers
Computer Systems
Oscilloscopes
Transmitters & Receivers
Sensors & Detectors
ANSI Standards
Low Frequency Amplifiers
Power Amplifiers
Number Systems
Regulated Power Supplies
Analogue Filters
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