Circuits & Schematics - Domestic - 2

A flashing LED signals the necessity to water a plant Very low current consumption - 3V powered circuit Circuit diagram: Parts: R1, R4 470K 1/4W Resistors R2 47K 1/2W Trimmer Cermet or Carbon R3 100K 1/4W Resistor R5 3K3 1/4W Resistor R6 15K 1/4W ...

Based on electromagnetic-field radiation. Place it under the pillow - Built-in timer. Circuit diagram: Parts: R1,R5 1K 1/4W Resistors R2 10K 1/4W Resistor R3,R6 10M 1/4W Resistors R4,R7 2M2 1/4W Resistors R8,R9 4K7 1/4W Resistors C1,C7 47µF ...

Double-tone Police sound Single-tone old ambulance sound Circuit diagram: Parts: R1,R3 470K 1/4W Resistors R2 680K 1/4W Resistor R4 82K 1/4W Resistor R5 330K 1/4W Resistor R6 10K 1/4W Resistor R7 33K 1/4W Resistor R8 3M3 1/4W Resistor C1,C5 ...

Build a dark-activated switch with only a triac, a photocell, and a resistor. Assume that you have a device that receives its power from the main 120 or 220V-ac line and you need to add a switch between the ac line and the device so that the device ...

Use this circuit to tell which game player presses a button first. Vasil Borodai The circuit in Figure 1 lets you indicate which game player presses a button first. Each button has a corresponding LED that indicates the pressing of the button. All ...

Max. range: 9,950 meters with two digits Slip it in pants' pocket for walking and jogging Circuit diagram: Parts: R1,R3 22K 1/4W Resistor R2 2M2 1/4W Resistor R4 1M 1/4W Resistor R5,R7,R8 4K7 1/4W Resistor R6 47R 1/4W Resistor R9 1K 1/4W Resistor ...

Particularly suitable for cellulite treatment 3V battery supply, portable set Circuit diagram : Parts: P1 4K7 Linear Potentiometer R1 180K 1/4W Resistor R2 1K8 1/4W Resistor (see Notes) R3 2K2 1/4W Resistor R4 100R 1/4W Resistor C1 100nF 63V ...

Compact circuitry using small-size parts only. Can be wired in parallel to existing switches Circuit diagram: Parts: R1 Photo resistor (any type) R2 100K 1W Resistor R3 200K 1/2W Trimmer Cermet R4,R7 470R 1/4W Resistors R5 12K 1/4W Resistor R6 1K ...

Continuous monitoring of the mains voltage is required in many ap- plications such as manual voltage stabilisers and motor pumps. An analogue voltmeter, though cheap, has many disadvantages as it has moving parts and is sensitive to vibrations. The ...

High sensitivity, portable temperature comparator detects draughts around doors, windows, etc. Circuit diagram: Parts: 22K Linear Potentiometer (See Notes) R2 15K @ 20 C n.t.c. Thermistor (See Notes) R3 10K ¼W Resistor R4, R5, R7, R9 22K ...