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Police Lights - These two circuits flash the left LEDs 3 times
then the right LEDs 3 times, then repeats. The only difference is the choice
of chips. |
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Police Siren - The Police Siren circuit uses two 555's to produce
an up-down wailing sound. The first 555 is wired as a low-frequency
oscillator to control the VOLTAGE CONTROL pin 5 of the second 555../..
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Powering A Project Negative Voltage - The safest way to power a
project is with a battery. Use 4 x AA cells in a holder or a 9v battery if
you only want to use the project for a short period of time. If you want to
use a 555 project for a long period of time you will need a "power
supply."…. |
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Power-Up Reset For Monostable Timers - Uses the LM555 timer or its
cousins with other letter prefixes. There can be minor differences between
555 timer IC's from different manufacturers but they all should be useable
for any circuit. Designed for Model Trains…. [from Rob Paisley's
Model Train web site] |
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Prescaler with Counter - Digital frequency counter is being used
for wide range of applications. Digital frequency counter extensively uses
digital.... |
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PWM Controller - This controller will deliver up to 30 amps and control the
motor from 5% to 95%. |
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PWM DC Motor Speed Control - This is a circuit for controlling the speed of
small DC motors, it works nicely as a speed controller for an HO or N gauge model
railroad… [Circuit Design by G. Forrest Cook] |
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Quiz - This project can be used for a quiz with up to 4 contestants (or
teams). Each contestant has a trigger push-switch and LED. When a trigger switch is
pressed it lights the corresponding LED, sounds the bleeper and prevents the other
trigger switches from working - therefore showing which contestant was the first to
press their switch.... [Designed by John Hewes] |
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Rain Alarm - This circuit consumes no current until moisture is detected on
the rain plate. |
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'Random' Flasher for 8 LEDs - This project uses a 4026 counter and display
driver IC to flash eight LEDs in an apparently random manner. It can be used to create
a display of your choice.… [Designed by John Hewes] |
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Reaction Timer Game - This is a game for two players. Player 1 presses the
START button. This resets the 4026 counter chip and starts the 555 oscillator.
The 555 produces 10 pulses per second and these are counted by the 4026 chip and
displayed on the 7-Segment display…. |
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Renewable Energy Powered Timer Relay Switch - Powering an AA battery powered
timer thermostat directly with a 12V power source…. [REUK - Renewable Energy UK
website] |
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Repeat Timer Circuit - Make a repeat timer circuit with large intervals
between ON times…. [REUK - Renewable Energy UK website] |
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Replacing 556 with two 555's - Here is a handy reference to replace a 556
dual timer with two 555's |
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RESET And CONTROL Input Terminal Notes - Uses the LM555 timer or its cousins
with other letter prefixes. There can be minor differences between 555 timer IC's from
different manufacturers but they all should be useable for any circuit.
Designed for Model Trains…. [from Rob Paisley's Model Train web site] |
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RESET Terminal - Currents And Voltages - Uses the LM555 timer or its cousins
with other letter prefixes. There can be minor differences between 555 timer IC's from
different manufacturers but they all should be useable for any circuit.
Designed for Model Trains…. [from Rob Paisley's Model Train web site] |
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Roulette - This circuit creates a rotating LED that starts very fast when a
finger touches the TOUCH WIRES. When the finger is removed, the rotation slows down
and finally stops. |
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RS - Flip-Flop Made With A LM556 Timer - Uses the LM555 timer or its cousins
with other letter prefixes. There can be minor differences between 555 timer IC's from
different manufacturers but they all should be useable for any circuit.
Designed for Model Trains…. [from Rob Paisley's Model Train web site] |
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Schmitt Trigger - Can also be called AN INVERTER or a SCHMITT INVERTER.
We have animated the circuit to show how the output goes high or low according to the
input level. The animation shows a wide gap between the input levels…. |
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Screamer Siren - Light Controlled - This circuit will produce an
ear-piercing scream, depending on the amount of light being detected by the Light
Dependent Resistor. |
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Servo Controller - his circuit can be used to manually turn a servo
clockwise and anti-clockwise. By pushing the forward or reverse button for a
short period of time you can control the rotation of the servo…. |
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Servo Motor Test Circuit (LM555) - This circuit while crude is an
inexpensive way to drive or test servo motor systems without the need for a compete
system….Circuit for model railroad trains…. [from Rob Paisley's Model Train web site] |
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Servo Tester - This circuit can be used to manually turn a servo clockwise
and anti-clockwise. By pushing the forward or reverse button for a short period
of time you can control the rotation of the servo. It will also test a servo….
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Simple Component and Continuity Tester - This simple project can be used to
test components, circuit board tracks, wires and connections.… [Designed by John Hewes] |
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Simple Electronic 'Lock' - There are six (or more) push switches. To
'unlock' you must press all the correct ones at the same time, but not press any of
the cancel switches. Pressing just one cancel switch will prevent the circuit
unlocking. When the circuit unlocks it actually just turns on an LED for about one
second, but it is intended to be adapted to turn on a relay which could be used to
switch on another circuit. Most relays cost about £2 to £3 extra.... [Designed by John
Hewes] |
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Simplest 555 Oscillator - The simplest 555 oscillator takes output pin 3 to
capacitor C1 via resistor R1. When the circuit is turned on, C1 is
uncharged and output pin 3 is HIGH. C1 charges via R1 and when Pin 6 detects 2/3 rail
voltage, output pin 3 goes LOW. R1 now discharges capacitor.... |
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Siren 100dB - This is a very loud siren and if two or more piezo's are
located in a room, the burglar does not know where the sound is coming from….
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Solid state Tesla Coil with 555 Timer - This is the more reliable version of
the one above. Self resonant circuitry is changed with a pulse generator. Yet very
simple in construction. Contents: Schematics, diagrams, PCBs, photos, videos, and
links to related experiments. ( Simple plasma globe and Simple Ion motor )….
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Square Wave Oscillator - It has adjustable (and settable) frequencies from
1Hz to 100kHz and is an ideal piece of Test Equipment. |
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Stall-Motor - Switch Machine Drivers (LM556) - The circuits on this page are
Switch Machine drivers that can be used to operate slow motion Stall-Motor type switch
machine motors. The circuits use LM556 dual timer chips to provide a PUSH-PULL output
to reverse the polarity of the voltage to the switch machine motors. The output of the
drivers is equivalent to a DPDT toggle switch.... [from Rob Paisley's Model Train web
site] |
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Stepper Motor Controller - The direction of rotation is determined by the
FORWARD and REVERSE switches and the motor does not take any current when a switch is
not pressed. |
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Stun Gun - This circuit produces a very high voltage and care must be used
to prevent getting a nasty shock. The transformer can produce over 1,000v and the
8-stage multiplier can produce up to 20,000v |
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Sweeping Output Siren - Uses the LM555 timer or its cousins with other
letter prefixes. There can be minor differences between 555 timer IC's from different
manufacturers but they all should be useable for any circuit. Designed for
Model Trains…. [from Rob Paisley's Model Train web site] |
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Switch Debounce - The output goes HIGH for 100mS when the switch is pressed.
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