Circuit Diagram

LED Holiday Lights Controller

Published:2011/8/1 3:14:00 Author:Felicity | Keyword: LED, Holiday Lights, Controller

Work of the circuit The circuit consists of Power supply circuit, pulse generator, the control circuit and LED display circuit. (It is showed in picture 1-165.) Power supply circuit consists of buck capacitor Cl, discharge resistors Rl, rectifier diodes VDl, VD2, voltage regulator diode VS and filter capacitor C2. Pulse generator consists of time-base integrated circuit ICl, resistors R2, R3 and capacitors C3, C4. The control circuit consists of decimal counting / pulse distributor circuit IC2, diodes VD3, resistors R4-R8, capacitor C5 and thyristor VTl-VW. LED display circuit consists of four word light displays. Each display consists of 16x16 arrays of 256 word light units. Each word light unit consists of LED VL, current limiting resistor R and the isolation diode VD4-VD7. (It is showed in picture 1-166.)   (View)

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AUDIBLE_ALARM_FOR_TIMER

Published:2009/7/13 4:28:00 Author:May

Used with 2-min timer for developing photographic paper, to produce short waming bleep indicating end of developing time. Input D is taken from output of Schmitt trigger that changes state when 2-min ramp generator times out. Tr9 and C4 to-gether lengthen short reset pulse so MVBR Tr10-Tr11 oscillates long enough for signal to be heard.-R. G. Wicker, Photographic Development Timer, Wireless World, April 1974,. p 87-90.   (View)

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CMOS_LOGIC_CONTROL_OF_300_W_LAMP

Published:2009/7/13 4:28:00 Author:May

Storage capacitor C2 in interface transistor circuit for typical CMOS gate charges to full +15 V supply voltage in time determined by R3 and C2, after which al is fired by positive-going differentiated pulse derived from input square wave. C2 then dumps its charge through R4 and C1, to fire triac C2 and energize AC load. For maximum load power, triac should be fired early in conduction angle. With 1-kHz input square wave, output power is over 98% of maximum possible.-A. Pshaenich, Interface Techniques Between Industrial Logic and Power Devices, Motorola, Phoenix, AZ, 1975, AN-712A, p 13.   (View)

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EXTERNAL_VOLTAGE_REFERENCE_WITH_BAR_GRAPH_DISPLAY_DRIVER

Published:2009/7/13 4:28:00 Author:May

Using external reference sources to produce (a) an adjustable 2 V and (b) up to +3V starting from +2 V.   (View)

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AUTOMATIC_TURNOFF

Published:2009/7/13 4:27:00 Author:May

Circuit removes bias from power Darlington about 15 s after both CONTINUE and BUSY signals go low, to conserve battery life in portable electronic equipment. Intecleaved copper patterns on printedcircuit board form touch switch that must be reactivated every 15 s or kept closed by finger contact while equipment is being used.-R.D.Wood, Replace Bulky Mechanical Switches with Touch Controls, EDN Magazine, April 20, 1978, p 132-133.   (View)

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CALCULATOR_COUNTER

Published:2009/7/13 4:27:00 Author:May

Normal arithmetic functions of National MM5736 calculator chip are preserved while providing counting capa-bility, through use of M0S transistors Q1-Q4.When reset switch is pushed, pin D1 is connected to pin K3 of calculator and calculator is cleared. C1 and C2 are discharged while S1 is closed but are charged when it is released, generating negative-going delayed pulse that causes a 1 to be entered into calculator. Delay allows clear function to Ue debounced by calculator chip. When S2 is in count mode, Q4 is turned on and D6 is tied to D4, for doubling maximum counting rate. Input pulse will now tum Q1 on, making calculator perform addition. Additional pulse adds 1 to sum. When S2 is rei turned to calculate position, keyboard Iogic is returned to normal state. MM74C00 NAND gates can be replaced with MM74C02 N0R gates, and M0S transistors can be replaced with MM5616 CMOS switch. -M. Watts, Calculator Chip Makes a Counter, National Semi-conductor, Santa Clara, CA, 1974, AN412, p 6.   (View)

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TWO_CASCADED_BAR_GRAPH_DISPLAY_DRIVERS

Published:2009/7/13 4:27:00 Author:May

This shows how to cascade two bar-graph dis-play drivers.   (View)

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BRIDGE_RECTIFIER_LED_LIGHT_STRING

Published:2009/7/13 4:26:00 Author:May

This circuit has a full-wave bridge rectifier feeding the LED string. With a 0.47-μF capacitor, as shown, the string's current was about 12 mA. If you substitute a 1-μF unit, the current will go up to about 20 mA, allowing you to add additional LEDs without suffering too severe a loss in brightness.   (View)

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50_KC_OPERATIONAL_AMPLIFIER

Published:2009/7/13 4:25:00 Author:May

Develops full rated output of 100 v into 10,000-ohm load up to 50 kc. Open-loop gain is 36 db.-H. Koerner, How to Extend Operational Amplifier Response, Electronics, 33:46, p 90-91.   (View)

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THREE_CASCADED_BAR_GRAPH_DISPLAY_DRIVERS

Published:2009/7/13 4:25:00 Author:May

This shows how to cascade three bar-graph display drivers. The basic scheme can be extended to four or more drivers, if desired.   (View)

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LED_AC_PILOT_LAMP_CIRCUIT

Published:2009/7/13 4:25:00 Author:May

This circuit places an LED in an ac circuit, where it operates as a pilot lamp. The capacitance value sets the LED's current. For 120-Vac operation, a 0.1-μF, 400-V capacitor will result in a 5- to 10-mA current, and a 0.22-μF unit will produce approximately 20 mA of current.   (View)

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f_NUMBER_FLASHMETER

Published:2009/7/13 4:24:00 Author:May

Used to measure light produced at subject position by electronic flashlamps prior to actual taking of picture.Meter is calibrated to read correct f-number setting of lens aperture. Three ranges are provided,from f/2 to f/64, while film speed selector covers films from ASA 12 to 650.Texas Instruments TIL77 photodiode is used as sensing element in probe. Article covers construction, operation, and calibration of meter in detail. Tablein article gives values for 18 resistors (one for each film speed) selected by S5. Examples are 20K for ASA 64 and 51K for ASA 25.-R. Lewis, Photographic Flashmeter, Wireless World,Aug.1974,p273-278.   (View)

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SURROUND_SOUND_INDICATOR

Published:2009/7/13 4:24:00 Author:May

The circuit indicates, with the aid of two LEDs, whether or not the input signal contains surround data. The criterion for this is the phase difference between the two channels: If this is zero, there is no surround data. In the circuit diagram, if there is a phase difference between the two channels, the output levels of comparators IC1b and IC1c will differ. These outputs are constantly compared by XOR gate IC2c; if there is a difference, the output of the gate will go high. Depending on the output state, the red or green half of D1will be actuated via gate IC2d, which is here connected as an inverter. If there is a pure surround signal, the red half will light brightly; if there is a mono signal, the green half will light. If the input is a standard stereo signal, the rapid changes in the output of IC2c will cause the diode to appear yellow-orange.   (View)

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16_KC_COMPENSATED_OPERATIONAL_AMPLIFIER

Published:2009/7/13 4:24:00 Author:May

Uses pentode V2A as voltage amplifier to provide up to 140 v peak signals at grid of output cathode follower V2A. Will go up to 50 kc without compensation,-H. Koerner, How to Extend Operational Amplifier Response/Electronics, 33:46, p 90-91.   (View)

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TIME_BASE_FOR_12_GHz_COUNTER

Published:2009/7/13 4:23:00 Author:May

Provides 1-s gate, latch strobing signals, 1-kHz signal for multiplexing displays, and digital sample rate control for high-frequency high-resolution counters. Timing chain divides 1.MHz external reference signal by 106 to give 1.Hz output. MC14534 five-decade counter generates 1-kHz multiplexing frequency with 20% duty cycle for blanking. Digital sample rate control is pro-grammed on BCD thumbwheel switch in incre-ments ranging from 1 to 9 s, using single MC14522 BCD down counter. -J. Roy, A Time Base and Control Logic Subsystem for High-Fre-quency, High-Resolution Counters, Motorola, Phoenix, AZ, 1975, EB-48.   (View)

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FULL_WAVE_CONTROL_

Published:2009/7/13 4:23:00 Author:May

Monsanto MCS6200 dual SCR optocoupler provides direct full-wave control of 15-W lamp or other AC device when driven by output logic voltages of microprocessor. LEDs are connected in series and photo-SCRs in reverse parallel to create equivalent of triac.-H. Olson, Controlling the Real World, BYTE, March 1978, p 174-177.   (View)

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SCR_LIGHT_DIMMER

Published:2009/7/13 4:23:00 Author:May

Provides full range of brightness control for up to 500w of lamps.Ujt Q1 provides turn.on pulses for scr-L.Stern, Thyristors Provide New Opportunities for Electronic Applications in the Home, Motorola Application Note AN-141, Dec.1965.   (View)

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ECONOMICAL_LED_BAR_DISPLAY

Published:2009/7/13 4:22:00 Author:May

A particular difficulty with LED bar displays is the high current drain. In the diagram, LED driver LM3914 controls a chain of LEDs instead of, as is usual, a number of parallel-connected LEDs. This means that in principle only a single diode current is needed to make several LEDs light. The cost of this, of course, is a higher supply voltage because account must be taken of a number of diode forward voltages. The economizing effect is strengthened if high-efficiency LEDs are used. In the diagram, the current drain of about 15 mA is less than half that of the standard application (32 mA).   (View)

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CALCULATOR_AS_COUNTER

Published:2009/7/13 4:21:00 Author:May

National MM5736 calculator chip is used with two DM75491 segment drivers and DM75492 digit driver for LED 6-digit display. Switches provide manual control of counter. To reset, push S1 to clear calculator, push S2 to enter a 1, then push S3 when new count is to be started. Current drive to LEDs is supplied by Vcc through cur rent-limiting resistors, giving power saving be-cause Vcc can be less than Vss. Will drive large LED display. -M. Watts, Calculator Chip Makes a Counter, National Semiconductor, Santa Clara, CA, 1974, AN-112, p 4.   (View)

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SOLID_STATE_MARKER_BEACON_RECEIVER

Published:2009/7/16 4:43:00 Author:Jessie

Three colored lamps glow in sequence during instrument landing system approach as 75-Mc receiver passes over three marker beacons modulated at 400, 1,300, and 3,900 cps respectively. Four-pole Butterworth filter ahead of first stage suppresses spurious response to 77.25-Mc carrier of television chanel 5. Single r-f stage isolates separate 68.75-Mc crystal controlled oscillator from antenna. Agc accomodates signals from 300 microvolts to 50 mv. -J. G. Robertson, Light-Airplane Marker-Beacon Receiver, Electronics,37:3, p 33-35.   (View)

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