PWM motor control

Pulse width modulation (PWM) is ad ideal for controlling small electric PCB drills that draw currents of up to 2 A. Larger currents are possible if T2 gets additional cooling and the value of C2 is increased. The design also makes use of the fact that the drill works with a small d.c. motor whose[…]

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DC-motor regulator

The regulator shown in the diagram enables the speed of a d.c. motor to be set over a wide range. Although the most frequently used method for achieving this is pulse-width modulation, in the present design pulse position modulation (also called pulse time modulation) is used. That is, rectangular modulator IC1 always switches the motor on for[…]

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Inductive proximity switch

Inductive proximity switches are used for instance for measuring motor speeds or determining the position of metal objects. They do not suffer from mechanical wear or contacts that spark. The latter is particularly important in spaces where explosive materials are stored. Virtually all commercial proximity switches are constructed as shown in fig 1. An inductor[…]

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RC- 5 infra-red receiver for 80C32 computer

‘RC-5’ is the Philips/Sony standard the received bits are shifted into a 16-hit reg-(JUL” for infra-red (IR) remote control of consistent formed by R4 (low) and R5 (hi0). The audio /video equipment (Ref. 1). The second start bit becomes the MSB. When the circuit and the listing were given enable the 80C32 received word is[…]

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