By means of a Relay, employed to drive a water pump, this circuit provides automatic level control of a water reservoir or well.
Published: May 25th, 2009
This circuit will emit an intermittent beep or will flash a LED when the water contained into a recipient has reached the desired level. If a deeper sensing level is needed, the clips can be extended by means of two pieces of stiff wire.
Published: May 25th, 2009
This DC to DC converter is built by the author for his 48V electric bike because he wanted to plug-in some common 12V accessories, that is, his cellphone charger, or a GPS unit.
Published: May 25th, 2009
Learn how to build an efficient boost converter to provide high voltage from a lower voltage greater than 5V for several applications, most prominently to charge capacitors. The boost converter described here utilizes the Astable operation of the NE555 a timer Integrated Circuit, an IGBT, a Diode, and an Inductor coil of wire.
Published: May 25th, 2009
An antenna is an electromagnetic device that collects or emits radio waves. It consists of material that conducts electricity arranged in such a way that it is in tune with the frequency of a radio signal. Like a tuning fork in the presence of a sound of the same pitch, an antenna tuned to a particular frequency will resonate to a radio signal of the same frequency.
Published: May 25th, 2009
The dipole antenna dates back to the early RF experiments of Heinrich Hertz in the late 19th century. It consists of a conductor that is broken in the center so that RF power can be applied to it. One can think of the half wave dipole as an open circuited transmission line that has been spread out, so that the transmission line can radiate a signal into space.
Published: May 25th, 2009
The digital clock of circuit, has as base one IC, the MM5314N, in which are contained all the circuits that need. The IC1 collaborates with six display of common anode, that are not critically as materials. You can select what dimension, you want it is enough you adapt pins their in the circuit. The display are drive by a system of polyplexis and are drive by thirteen transistors. For timing the circuit, is used the frequency of network 50HZ.
Published: May 25th, 2009
It is a classic designing of final amplifier 35 W, with two EL34 in push-pull, from the Siemens and Halske.
Published: May 25th, 2009
This is a 3 channel RF remote control project.The transmitter powered by 3V battery range about 10 m.This remote control I use PIC12F509 from Microchip which is a 8-pin single-chip microcontroller designed for low pin count applications with 1 K words flash memory and 41Byte SRAM and some special features such Power-saving Sleep mode,Wake-up from Sleep on pin change.
Published: May 21st, 2009
This circuit is useful in liquids level or proximity detection. It operates detecting the distance from the target by reflection of an infrared beam. It can safely detect the level of a liquid in a tank without any contact with the liquid itself.
Published: May 21st, 2009
This circuit is a simple wire loop alarm that can be used in doorways, hallways, or any other place the tripwire will be broken by intruders. The circuit has a built in siren, but it can be replaced by a relay to drive an external siren, commercial alarm, etc.
Published: May 21st, 2009
This simple pulse width modulation DC motor controls the motor speed by driving the motor with short pulses. These pulses vary in duration to change the speed of the motor. The longer the pulses, the faster the motor turns, and vice versa.
Published: May 21st, 2009
This AC motor speed controller can handle most universal type (brushed) AC motors and other loads up to about 250W. It works in much the same was a light dimmer circuit, by chopping part of the AC waveform off to effectively control voltage. Because of this functionality, the circuit will work for a wide variety of loads including incandescent light bulbs, heating elements, brushed AC motors and some transformers.
Published: May 21st, 2009
This circuit is a fan controller which is using the pulse width modulation method. It is tiny and easy to build.
Published: May 3rd, 2009
A tachometer is still just as useful. By performing RPM measurements from time to time, problems such as a bad cell in the battery, deteriorating connectors, or damaged motor windings can be detected early before there\'s a major failure.
Published: May 3rd, 2009
Bruce project, is a EL84/6BQ5 Push-Pull Tube Amplifier. The driver stage is an SRPP with ECC802S tubes, while ultra linear operation is used for the output stage with Sovtek EL84 tubes. LM317 Regulators are used for constant current sources CCS of the output stages. 12VDC is used for the tube heaters.
Published: May 3rd, 2009
A small 325mW amplifier with a voltage gain of 200 that can be used as a bench amplifier, signal tracer or used to amplify the output from personal radios, etc. The circuit is based on the National Semiconductor LM386 amplifier.
Published: May 3rd, 2009
This simple circuit is the electronic version of the combination lock. Using the special purpose LS7220 digital lock IC, the circuit allows a 4 digit combination of your choice to activate a relay for a set period of time. This relay can then be used to trigger a lock solenoid, enable a starter button, open a motorized door, or many other tasks that require a momentary signal.
Published: May 3rd, 2009
This simple circuit uses an incandescent lamp to detect airflow. With the filament exposed to air, a constant current source is used to slightly heat the filament. As it is heated, the resistance increases. As air flows over the filament it cools down, thus lowering the resistance. A comparator is used to detect this difference and light an LED. With a few changes, the circuit can be connected to a meter or ADC to provide an estimation on the amount of air flow.
Published: May 3rd, 2009
It is a little wisp of a circuit that allows you to drive a blue or white LED from a low voltage. Normally, if you want to light up a blue or white LED you need to provide it with 3 - 3.5 V, like from a 3 V lithium coin cell. But a 1.5 V battery like a AA cell simply will not work.
Published: April 22nd, 2009