Panel switch wiring

Thursday, October 2, 2014

Temperature Data Logger 4 Channel Four Channel

Heres a temperature data logger circuit, an 8-pin microcontroller based circuit for temperature data logging via the serial port of any computer from between 1 and 4 remote digital temperature sensors, DS1820/DS18S20 made by Dallas.

Features of the Temperature Data Logger are are follow:

Provides realtime data via the serial port.
Interfaces up to 4 x DS1820 sensors.
Accuracy to 0.5 degrees centigrade
Fahrenheit scale selected by a jumper
No external power required
Data stream easily logged & processed.
Over 200m distance for each sensor

The sensors of temperature data logger may be located more than 200 yards from the PCB. Just check that the remote VDD is above 4.4Volts. Its recommends 10uF tantalum capacitors be placed across the power supply pins (not supplied) to minimise random errors and possibly get increased range.

Download :
- Circuit Schematic and Parts List
- Sensor Specs DS1820 DS18S20
- Software for Windows and DOS
- Source Code
- Terminal Emulator

20W Bridge Audio Amplifier based on TDA2005

This is 20W Bridge Audio Amplifier schema based on the TDA2005 IC, a class B dual audio amplifier, specifically designed for car radio applications etc.
This schema require Voltage input 18 VDC and will give you Output power - 20 W, 4 Ω

This is the amplifier kit:

This is the schematic:

To get the schematic diagram, component list and component layout, please download this file

Simple 555 Based Alarm Wiring diagram Schematic

This is a Simple 555 Based Alarm Circuit Diagram.The alarm schema has a single 555 oscillator/timer (Ul) performing double duty; serving both in the alarm-trigger schema arid the entry- delay schema. In this application, the trigger input of IJ1 at pin 2 is held high via Rl. A normally-closed sensor switch, SI, supplies a positive voltage to the junction of R2 and CI, and lights LED1.

Simple 555 Based Alarm Circuit Diagram

With both ends of CI tied high, there is no charge on CI. But when SI opens, CI (initially acting as a short) momentarily pulls pin 2 of Ul low, triggering the timed delay circle.At the beginning of the timing cycle, Ul produces a positive voltage at pin 3, which charges C4 to near the positive voltage at pin 3, which charges C4 to near the positive supply voltage.

Transistor Q1 is heavily biased on by R3, keeping its collector at near ground level. With Q1 on, SCRl`s gate is clamped to ground, holding it off. When the delay schema times out, pin 3 of Ul goes low and ties the positive end of C4 to ground. That turns Q1 off.When Q1 turns off, the voltage at the gate of SCR goes positive, turning on the SCR and sounding the alarm. The delay time is adjustable from just a few seconds (R6 set to its minimum resistance) to about one minute (R6 adjusted to its maximum resistance).