Two Wire Stepper Motor Positioner

Two Wire Stepper Motor Positioner

Figure 2 is a diagram of the control circuit built on a 1.45 X 1.8 inch PC board. IC1 is an LMC555 CMOS timer that generates a 200 microsecond wide clock pulses to step the motor and control its speed. The speed can be varied by changing the pulse repetition rate with R1.

Fan Control for Processor Systems Using the LM85

The LM85 hardware monitor includes three PWM outputs that can be used to control fan drive circuitry. In addition, the LM85 features the ability to monitor five different power supply voltages, four fan tachometer outputs, and one set of processor voltage regulator module VID outputs.

PWM Motor/Light Controller

These two schematics are variations on another PWM circuit that I designed. The diagrams are for 12V operation only and there are high side (common ground) and low side (common +12V) versions. The low side version of the circuit uses an N Channel FET, the high side version of the circuit uses a P...

multiple temperature fan speed

The block diagram in Figure 1 represents a complete remote-temperature-sensing and fan-control system. The system uses an Analog Devices temperature-monitor and fan-control ASIC and a PIC16C84 µC from Microchip Technology. The ADM1022 allows you to measure the local temperature and two remote...

Motor direction controller

This circuit can control a small DC motor, like the one in a tape recorder. When both the points A & B are "HIGH" Q1 and Q2 are in saturation. Hence the bases of Q3 to Q6 are grounded. Hence Q3,Q5 are OFF and Q4,Q6 are ON . The voltages at both the motor terminals is the same and hence the motor...

Position detectors provide motor-control logic

In the circuit of Figure 1, assume that a brush-type dc motor must drive a load back and forth between two endpoints on a lead screw. Optical sensors determine end of travel, and an SPDT switch selects to which end to send the load. The sensors themselves supply all the necessary directional...

Universal motor speed control

The resistor capacitor network R1-R2-C1 provides a ramp-type reference voltage superimposed on top of a dc voltage adjustable with the speed-setting potentiometer R2. This reference voltage appearing at the wiper of R2 is balanced against the residual counter emf of the motor through the SCR...

Chloroplast solar engines

The heart of the Chloroplast is the Motorola MC34164-3 Micro power Undervoltage Sensing Circuit (U1 in the following diagram). In normal use, this component monitors the voltage at pin 2, and applies a ground at pin 1 ( out ) when the monitored voltage drops below 3V (34164-3 monitors 3 volts,...