Power Control

Lighting auto controller

The governor following is intended to regulate the light intensity incandescent 220 V. The components in a relatively few, which means it can easily be mounted onto a small plate. After the build, we recommend you place it inside the box which is flush mounted switch ON / OFF the lamp. Setting the switch to ON, the lamp will light after about 400 msec, a delay is probably negligible. But when the state enters the ON OFF, then mesolathei a period of 20 sec, the brightness of the lamp remains unchanged to start falling out soon after. ..

Automatic switch for batteries

Nowadays the batteries are gaining more and more power, being the only components that fail to provide energy for portable electronic devices. The evolution is rapid, leading manufacturers electronic equipment to attempt to minimize the consumption of their products so that they can operate for several hours using simple batteries trade. In spite of the efforts of manufacturers, the device will absorb a zero power not yet invented. Thus, both small and if the current device is mathematically certain that at some point, after a few hours, days or ethdomades, the battery-drain '. The purpose of the circuit will describe below, is to keep 'alive' batteries for the maximum time, minimizing unnecessary consumption...

Automatic Level Control Signal Circuit

Involvement is a modified version of the classic circuit of automatic level control signal used in tape recorders. The purchase price of the components (using TL072) does not exceed CZK 60 for a channel. For a range of entry level audio signal may be replaced by the operation, which would be matched signal level so as not to overmodulation or podmodulován. The device performs a kind of correction pseudointeligentní volume. The circuit is also under the control settings and time constants trimmer member RC nabíjeného output signal through a silicon rectifier diodes and function of compressor frequency signal, which means that it reduces the dynamic range (the ratio of the loudest / quietest signal for a certain period of time)...

Moisture detector with pump controller

This moisture detector with pump controller is built around the special purpose LM1830 IC. The LM1830 is designed to detect moisture by passing an AC current through a set of probes. An internal comparator compares the resistance of the probes to an internal reference. When the resistance between the probes is low (indicating the presence of water or other conductive liquid) then the IC triggers it's output. An AC signal avoids electroplating and corrosion problems that are common when DC is used. To provide an adjustable delay hysteresis to avoid cycling the pump, a timer based around the 555 is used a range of about 5 seconds to two minutes. In this way the pump will stay active for a set amount of time even if the fluid level is below that of the probes...

Auto poweroff for power supplies circuit

Probably the easiest way of doing automatic switch off is with relay logic. In the diagram, the box marked RL1 is the coil, the 2 in the coil box tells you there are two sets of contacts somewhere on the circuit, operated by this coil. In this simple circuit, it's easy to see them!Sw1 is a momentary push switch. When it's pushed (contacts closed), voltage from In is applied to the coil so the relay operates. RL1/1 (the first set of contacts on RL1) closes and applies power to Out. RL1/2 closes at the same time and shorts out Sw1, maintaining power to the relay coil. So Sw1 is a push to switch on and the circuit is a relay bistable - bistable as it has two stable states, on and off...

220V Mains Quality Monitor

With this circuit you will be able to monitor the quality of the mains. There are 4 distinct sections, each supervising a parameter pertinent to the quality of the supply line. The noise section consists of a 50Hz filter and a speaker where you will hear the noise present on the line. The bicolor LED should be adjusted for the least light with the 5k pot and gives a visual indication of noise or asymmetry in the wave. The second section will detect any spike which is overimposed on the mains voltage: adjust the pot so that it will not trip if you just switch on the light, sensitivity is high enough to detect a switching operation from a close neighbor. ..

Electronic fuse circuit

Full short-circuit and overcurrent protection is given by this circuit suitable for workbench applications in technical schools and laboratories where there is a need to work directly with the mains. Additional features are a clearly visible red lamp indicating that the voltage is present, good isolation of the output circuit when the unit is off, only a few millivolts were measured with no load, current threshold adjustable over a limited range and the possibility of remote cutout: the 6V from the secondary can be taken anywhere, normally where you are working, even far away from the protection circuit. ..

Water Level control and monitor with PIC12F675

I found some similar circuits but aren't good enough for me. Some circuits measure the water's resistance to determine the level. That is dangerous for drinking water (contamination) or explosive liquids because electricity is in contact with water. The Pressure sensor have a tube. The tube end on the botton of the tank. When the liquid fill the tank, the pressure inside the tube increase. The 12F675 have A/D converters. The PIC measure the pressure and light up the led corresponding to the liquid level. Green LED = Full, Yellow = Half, Red = Almost Empty. When the tank is completely empty, It turn on the Water pump or activate the buzzer...

Serial IR transmitter using PIC16F628

This is a programmable infrared (remote control) transmitter, which can be controlled from a PC serial port. It is capable of sending many remote control formats, including the Philips RC-5 standard. The controller will accept commands on the serial port. Settings are: 19200 bps, 8 bits, no parity, 1 stopbit, no flow control (XON/XOFF or RTS/CTS). Commands consist of hex coded bytes and must be written on the port as ASCII characters separated by space, terminated by ENTER (ASCII char 0d). You can use a terminal emulator program to test out the circuit (for example minicom on linux, NC terminal on DOS, or hyperterminal on windows), but the settings usually won't work at first, so it is recommended that you write a small program to set the parameters and send commands by pressing keys on the keyboard...

Backup Power System with PIC16F870

The PIC16F870 keeps track of battery voltage as well as both charging and discharging currents. It also drives the 4 digit display, and switches the AC and load relays. The basic operation is as follows: While AC power is available, the battery voltage is constantly monitored and topped off as needed. When the AC power fails, the load relay engages the 12-volt system. This connects to lights, fans, and other 12 volt devices as needed. Should the battery voltage fall too low, the load relay is disengaged, preventing the acid batteries from being damaged by over discharging...

PIC hydro system controller

The ELC presented here has some flexibility, thanks to being software-controlled, but also has its limitations: It's intended for microhydro systems that employ a single-phase synchronous alternator, working at 220-240V, 50Hz, in a power range up to 25 kilowatts, and using up to eight dump loads, some or all of which can be "useful" loads, such as water boilers or room heaters. It can be built for 120V systems too, simply by using the proper power transformer, but then it will be limited to half the power. It can also be configured for 60Hz (or any other reasonable frequency) simply by setting a parameter in the software. In the form presented here, four of the outputs are used in prioritized fashion, with the other four having all the same (last) priority, with power being distributed among them. ..

2500W Phase Control with TLE3103

This circuit controls resistive and inductive loads up to 2,500W. Its main functional device is an integrated phase control circuit - Siemens TLE3103. It contains its own power supply, a zero voltage crossing detector circuit and a logic driver. An additional feature is the low voltage input to enable/disable triac firing enabling/disabling the logic driver. The function is as follows: pin13 TLE3103 open (floating), trigger output active, tied to ground trigger output disabled...

There are a number of ways to obtain the low voltages required to run small projects from the wall power outlet. The simplest way is to buy a factory-built molded supply which is designed to plug directly into the wall outlet. Some such supplies have an internal voltage regulator and need no additional parts, others provide an unregulated DC voltage and many are simply AC transformers in a box. The regulated types offer less power output for a given size with currents limited to a couple of hundred milliamps but the AC transformer types can provide several amps. ..

This circuit adds a power down function to analog I/O ports (for example, the AD7769 and AD7774). Moreover, the diodes ordinarily needed to protect the devices against power-supply missequencing can be eliminated Bringing the power down control high (+5V) applies power to the controlled circuit by turning on all MOSFETs. Specifically, raising the power down brings the output of U1C low, causing capacitor C1 to discharge VOL exponentially with time constant R1C1. As the voltage on C1 falls, two events occur...

It is important to know that transistors Q1,Q2,Q3 must not work like an astable (tri-phase) multivibrator (you could verify it on scope (no square waves but NON LINEAR wave between XB, YB, ZB must be displayed on the scope)...