Power-consumption-limiter


Posted on Dec 19, 2012

A simple solenoid driver uses incandescent lamp filaments as on-indicators to limit power consumption. High magnetic reluctance (opposition to flux) in the coil of an armature-driven device, such as a solenoid or relay, calls for a surge of activation current, followed hy a lower de level to remain on, since surge to on-current ratio is typically 5:1. The cold filament allows a surge of coil-activation current to pass through;


Power-consumption-limiter
Click here to download the full size of the above Circuit.

as the filament heats up, it throttles the current to a more reasonable hold value. The solenoid driver circuit offers these features: 5-V logic swings turn the power-MOSFET switch, Q1, fully on and off. 1vo low-cost flashlight lamps, in parallel, handle the peak current. Because their de current is only 50% of peak and because they operate at 60% of their rated voltage, the lamps have an operating life of 12,000 hours. Further, the lamp filaments" positive temperature coefficients raise each filament"s resistance. This rise in resistance eliminates current-hogging problems and provides short -circuit protection. The steady-state on-current is 700 mA, vs. 1700 mA without the lamps. A 4.6-V min supply rating allows battery operation.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Function Generator Sine / Triangle / Square / Saw ( PIC16F870 )
50Ohm driver
Two Colour LED Light Bar Circuit Schematic Diagram
Application of MSP430F149 one-chip computer in the target designator design
a voltage-controlled current sink / voltage-controlled resistor
OIRT Tuner
operational amplifier op amp oscillator
Simple Telephone Timer Circuit PCB
LC feedback Oscillator
Atmel 89 Series Flash Programmer Ver 3.0
autoconnect disconnect battery charger
Direct FM
INA321 322 a direct drive capacitive input of the A D converter Figure
Lab Variable Symmetric Power Supply circuit 2x30V 3.5A



Top