Newest circuit diagrams

6 Zone Alarm with 7 Segment Display

This alarm system has 6 independent zones, 1 timed entry/exit zone, a 7 segment LED display and a test or walkthrough facility. Suitable for a small office or home environment, it can also be adapted to use a combination lock or keypad to set and reset the alarm.

TDA2030 8w Amplifier

An 8 watt amplifier made with the TDA2030 IC. Built two such units for a stereo amplifier.

Self-powered Fast Battery-Tester

Tests 1.5 to 15 Volt cells Two-LED display, no power supply required

Gate Alarm

A cheap and simple gate alarm made from a single CMOS Integrated Circuit.

Snore Alarm

The idea behind this snore alarm, is just to rouse the snorer, not the entire household. To wake the sleeper, vibration is used, not an audible alert. The vibration is provided by a small motor housed in a small 35mm film case, which can be placed under the sleepers mattress or pillow. This circuit has a level control and peak display indicator, a variable trigger threshold and trigger indication.

Arduino MQ-7 Carbon Monoxide Sensor Circuit

The carbon monoxide sensor we will use is the MQ-7 sensor. This is a sensor that is sensitive to effects of CO. Carbon monoxide (CO) is a very dangerous gas which is odorless, colorless, and tasteless, so it cannot be smelt, seen, or tasted. A person really would have no idea that they are breathing in CO besides the fact that they would start to feel horrible.

Digital Combination Lock

A multiple input combination loack using CMOS counter IC's. Flexibility and code change is allowed by changing output connections.

60W Bass Amplifier

Low-cut and Bass controls. Output power: 40W into 8 Ohm and 60W into 4 Ohm loads

Blinking Arrow

17 LEDs in four groups bar-mode sequence. Suitable for shop-windows animation etc.

Ultra-simple Voltage Probe

Detects 1.8 to 230 Volts DC or AC Minimum parts counting