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Last Updated
03/31/2019
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Detailed entries for one subject from the INDEX TO HOW TO DO IT INFORMATION. |
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TIMER sa CLOCK sa COUNTER sa HOURGLASS sa METRONOME sa PHOTOGRAPHIC DARKROOM TIMER sa REACTION TIMING sa STOPWATCH sa TIMER -- ELECTRONIC sa TIMER -- MECHANICAL sa TIMER-CONTROLLED SWITCH xx COUNTER Electronic circuit for a simple timer which will measure up to 7 minutes. Touch plate starts the timer. An alarm sounds after elapsed time. Est. cost: $10. Electronic circuit for a multi-stage timer. Use it to time up to five sequential periods, each ranging from a few seconds to 15 minutes or more. Est. cost: $10. A long-interval alarm timer (hours or days up to two weeks maximum) sounds an alarm when the interval has elapsed. Semiconductor gate-controlled switch makes practical an all-electronic timer that can be set from 1 to 100 seconds in discrete 1-second steps. Est. cost: $45. Integrated circuit, digital interval timer. Has four timing ranges, each divided in 15 discrete steps. Can measure event intervals from 0.05 to 15 seconds. Beeping electronic timer can be varied from one pulse every 3/4 second to 3.5 pulses per second. Est. cost: $12. Ultra-simple and inexpensive elapsed time meter can be used to measure how long electrical devices are drawing current. Built around a 555-type IC. Adapt a common electronic pocket calculator to be a timer which counts elapsed seconds, minutes, hours or other programmed intervals. It can also count down to zero from a starting number. The calculator may still be used by unplugging it from the accessory timing circuit. Easy-to-build, simple tester for surplus 555 intergrated circuit timer chips. Flashing lamps signal a good chip. Space cushion timer. Electronic timer sounds a beep 2.1 seconds after being activated. Installed on your automobile dashboard, it is used to help avoid tailgating the car ahead. Crystal controlled digital timer measures periods from 1 to 99-minutes. Powered by 9-volt battery. A buzzer sounds for seven seconds when elapsed time has passed. Long delay timer uses the new EXAR XR-2242 timer IC, consisting of a long-delay timer and a very low frequency oscillator in a 8-pin chip. Adjustable timing circuit incorporates the NE555 oscillator/timer IC, two LED's, a reset switch. Pick-a-number counter and timer. Using an IC counter (such as the 4040) to provide counts and timing intervals in addition to its designed count outputs. Circuit for a one-minute timer. CMOS phase-locked loops, the "Cinderella" of precision timing circuits. Part 1. Low-power, monostable timer for a battery-operated circuit. Unusual timer circuit uses an SCR (silicon-controlled rectifier). All about timer IC's. Experiments to explain the operation of the 555 timer IC and build useful circuits using the 555 timer. Circuits include astable and monostable multivibrators. Use the 555 timer IC to build a battery powered beeper which features adjustable timing and tone. Simple circuit will emit an audible beeb every ten minutes. Used by ham radio operators to remind them to identify their station. Circuit for a multi-stage timer. Use to time up to five sequential periods, ranging from a few seconds to 15 minutes for more. Each time period is signaled by a different LED which lights in sequence. Est. cost: $10. Downcounter timer for games. Preset this unit to count down to zero from any time up to 99 minutes and 59 seconds. Useful for games like chess where moves must be made within a prescribed time limit. Buzzer signals the end of time. Circuit for a timer to count off 20 seconds. Operates on 120-volts. How to use IC timers. Typical circuits which use the 555, 2240, 2250 and 2260 IC timers are shown. Universal timer. A two-stage timer that can be latched on, that can be set for continuous operation, that can be used for a time-delayed alarm operated by a photocell, and other applications. The timer is built around a single 4011 quad NAND gate. The versatile 555: How it works and how to use it. A comprehensive examination of one of the most popular integrated circuit timers along with guidelines with how you can use it in your own projects. Programmable timebase/dividers. Use them in clocks, computers, and other digital circuits, or as additions to your test-equipment lineup. Two circuits shown. (1) Output of 1 pulse per second (1 Hz) from a 50- or 60-Hz source. Est. cost: $14. (2) 1 pulse per second from a 1-MHz crystal source. Est. cost: $20. Electronic timer counts down to zero from 1 through 10 minutes. Sounds a beeper when the time has elapsed. Experimenting with the power MOSFET (MOS field-effect transistors). Includes circuits for a simple audio amplifier, linear lamp dimmer, pulse-driven light dimmer, lamp flasher, and timer circuits. How to design ultra-long-delay timers. Timing delays from a few microseconds to almost 30 days can be obtained from an inexpensive programmable timer chip. Includes a circuit for a "timer beeper" to sound an audible alert when the count-down cycle has timed out. Tip: Use coax cable or twisted pair wiring to create time delays in the 1-nanosecond to several microsecond range. Using the LS7210 timer chip. This versatile IC lets you program time delays ranging from a few milliseconds to hours and even days. Nonvolatile event timers and totalizers. A look at a miniature mercury elapsed-time indicator (coulometer) and a mechanical counter. Supertrol, a free-running master sequence generator which provides a completely adjustable on/off ratio from 50 milliseconds to 10 seconds. Use for automatic start switching, interval timing, voltage sensing, delayed stop action, etc. An application of the Schmitt trigger circuit. Firing-range timer. Automatic audible timer will beep at precise 10 or 20 second intervals. Circuit for a 1-transistor electronic timer which can be varied between 6 and 60 seconds. Electronic timer gives a digital readout up to 9 minutes and 59.999 seconds. Useful for timing sports events. Many methods can be used to start and stop the timer. Time-period module designed to be used with the digital measurements lab described in the November 1970 issue. Has a range of 0.01 to 15 seconds. Est. cost: $39. Circuit for use in an audible timer or electronic metronome. Circuit for a FET interval timer that can be set for 1 to 101 seconds. Electronic timer circuit uses only one IC and four components. Can time from 10 microseconds to 1000 seconds. Six typical circuits are shown. A look at the 555 IC timer chip and some of the many uses to which it can be put. Applications for the 555 integrated circuit timer chip described in the Nov 1973 issue (p.54). Applications include: (1) Warble alarm circuit, (2) Schmitt trigger or bistable buffer, (3) Square wave oscillator, (4) Output drive considerations, (5) Wide-range pulse generator. More circuits using the 555 IC timer include (1) tone generator, (2) code practice oscillator, (3) CW monitor and (4) electric-eye annunciator. The "Executive Digital Temper Countdowner" displays numerals from zero to nine, then sounds an alarm. A digital timer-scoreboard for athletic events. Gymnasium-sized digital readouts simultaneously time up or down and keep score. Numerals are about 1-ft. high. Est. cost: $100. Sixty second interval timer. Pushing a button turns off an LED for exactly 60 seconds. Build this 5-minute on, 1-minute off timer to help you comply with FCC regulations. A red, yellow, and green light tells you what you can (or should) be doing now. Electronic "talk timer" for public speakers. Can be set for 5 to 60 minutes. A second timer for the "summarize" period can be set for 5 to 15 minutes. A green light glows during the talk period, a yellow light during the summarize period, then a red light. Est. cost: $30. A look at the 556 IC timer. How it works and typical circuits. The 556 is actually two 555 timers in a single 14-pin DIP. How to program an HP-25 for use as a digital clock and timer. Information on using the LM322 precision timer integrated circuit. Build a fail safe timer. Simple timer circuit uses two 555 IC's. It will sound an alarm when the time period has elapsed. An LED indicates that the timer circuit has been activated. Build a universal electronic timer. Time any event occurring in a 24 hour period. Includes an audible alert and automatic on/off. Est. cost: $35. How to determine the duty cycle of a 555 timer IC. Using the 555 timer IC in interval timer circuits and monostable multivibrators or "one-shots". Circuits for missing-pulse detectors and slot switches use 555 and 556 ICs. Such circuits may be found in intrusion alarms and adjustable-duration event timers. Tips on getting long time delays with 555 or 556 IC timer chips. Modifying electronic calculators to perform other functions, including: event-counter, timer, digital controller, etc. Using the 4060 series CMOS device as a timer (in place of the 555 timer). Ultra-simple timer circuit uses a field-effect transistor (FET). Add a relay to control another circuit. Circuit for a sound-activated battery-powered electronic timer. Build the time-on recorder. Tells you at a glance how long an appliance or TV receiver has been operating. RC timer circuit can time delays of a few seconds to several hours and can be set by selecting the proper charging resistor. The timer's output can be monitored by observing the status of the two LED's. 555-timer circuit calculation program, written in BASIC, makes two types of computations. (1) Calculate circuit data from the component values. (2) Calculate component values from circuit data. Putting RC (resistor-capacitor) networks to work. Learn how to keep time using circuits you can design with just one equation. Digital, programmable timer circuits which use CMOS devices instead of the 555 oscillator/timer IC. (1) 16-stage binary counter. (2) 24-stage, binary-ripple counter. Electronic egg timer is built inside a plastic pill bottle. Can be built to time from 2 to 6 minutes. Turning the bottle upside down starts the timer and turns on a lamp, which goes out when the time has elapsed. A review of various IC timers, how they work, and typical circuits. Includes the 555, 7490, and 7448. Long duration IC timers that really work. Delays of many hours or days can be precisely timed by combining multivibrators with binary counters. Here is how the setup operates. All about selecting and using universal electronic counters/timers. Basic timing circuit uses four Schmitt gates. Use it to time eggs, telephone calls, etc. Versatile electronic timing circuit that can be used for any number of timing sequences and uses only one digital clock. Using the ZN1034E IC as part of long-time timer circuits (1 second up to 19 days). It is more accurate than the 555 timer IC for longer periods. Very simple delay circuits which will accept a trigger pulse, wait a specified length of time, and then output another pulse. Simple time-delay circuit uses the 555 timer IC. Suitable for use in an alarm system. Electronic "beeper box" eliminates stray noises when shortwave signals are being recorded on tape cassettes. It also allows putting distinctive marker sounds on the tape. Later analysis of such tapes allows the precise times of astronomical events to be determined. | |||||||||
Copyright © by Norman Lathrop Enterprises. All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means (electronic, mechanical, print photocopying, recording or otherwise) without the prior expressed permission of Norman Lathrop Enterprises, except as permitted by law. |
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