Electronic Circuit Breaker:  This circuit uses the on-resistance of the MOSFET as the current sensor. Reset it by removing the input power or the load. The circuit draws no current unless tripped.  Designed by Andrew R. Morris  (added 09/05)

Electronic fuse emulates fast  or Slow BLow fuses:  11/09/00 EDN-Design Ideas / (Electronic circuit added 5/02) The electronic-fuse circuit in Figure 1 combines the properties of a current transducer and a solid-state relay to disconnect low power at preset levels. Using this circuit lets you avoid the bother of stocking and replacing fusible links. The circu...

Electronic Fuzing:  National Semiconductor Application Note 05-Aug-1995 (added 8/02)

Electronic Security System:  (Electronic Circuit / Schematic added 10/04)

Equip switchers with overCurrent protection:  06/24/99 EDN-Design Ideas  (added 2/06)

Failed Power Light:  turns on small low voltage lighting when mains power disappears (Circuit / schematic design added 6/06)

FAILSAFE Biasing of Differential Buses:  National Semiconductor - Application Note   (Circuit / schematic design added 6/06)

Failsafe Biasing of LVDS Interfaces:  National Semiconductor - Application Note   (Circuit / schematic design added 6/06)

Fail-Safe Monitoring and Clock Frequency Switching using the PIC16f684:  Microchip Application Note - Published 16-Dec-03   (Circuit / schematic design added 6/06)

Fast Electronic Fuse:  A fast electronic fuse designed to operate on 230V AC with an adjustable trip current. (added 10/05)

Fast IC Power Transistor with Thermal Protection:  National Semiconductor - Application Note   (added 2/06)

Fault latch circuit protects Switchers:  02/19/04 EDN Design Ideas  /  (added 1/05)  Many power-supply designers like to have a regulator latch off in the event of an overcurrent situation or other fault condition. Yet, many PWM controllers do not internally support this latch-off function. Most do, however, have a power-good output and an enable function. The circuit in Figure 1 adds that latch-off capability at low cost in little additional space....

For want of circuit-protection devices:  02/03/97 EDN-Design Feature / (added 2/06)    A variety of devices protects sensitive circuits against overvoltage or overcurrent conditions, thereby preventing overheating, avalanche breakdown, and device burnouts. —Bill Travis, Senior Technical Editor

Fuse Blown Indicator:  It came to me in a flash. A simple way to see if a fuse has blown without removing it from its holder. Its not often you can design a circuit using just two components, but with just one resistor and an LED this circuit provides visual indication of when a fuse has blown....   (added 10/05)

Ground Fault Interrupter #2:  National Semiconductor Application Note MP1851 June 1992 (Electronic circuit design added 02/05)

Ground Fault Interrupter:  (Electronic circuit design added 02/05)

High Side Driver has Fault Protection:  09/05/02 EDN Design Ideas  /  (added 1/05)  High-side drivers find common use in driving grounded solenoid coils and other loads. Short-circuit protection for such drivers is essential for avoiding damage from wiring faults and other causes. Polymer fuses are generally too slow, and discrete current-limiting circuits are large and cumbersome. The circuit in Figure 1 uses a small, low-dropout linear regulator as a high-side switch and p......

High Voltage Circuit Breaker Protects to 26V:  09/11/98 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)  

High-Side Driver has Fault Protection :  09/05/02 EDN Design Ideas (added 1/05)  High-side drivers find common use in driving grounded solenoid coils and other loads. Short-circuit protection for such drivers is essential for avoiding damage from wiring faults and other causes. Polymer fuses are generally too slow, and discrete current-limiting circuits are large and cumbersome. The circuit in Figure 1 uses a small, low-dropout linear regulator as a high-side switch and p......

High-Voltage circuit breaker protects to 26V :  09/11/98 EDN-Design Ideas  / (added 2/06)

House Security System:  (Electronic Circuit / Schematic added 10/04)

IC Controlled Emergency Light with Charger:  (Electronic Circuit / Schematic added 10/04)

Impedance Transformer flags failed fuse:  12/17/04 EDN Design Ideas  /  (added 1/05)  Figure 1depicts a circuit that detects the opening of a miniature circuit breaker or high-rupture-capability fuse in a high-reliability telecommunications power supply. The circuit generates an alarm when a failure changes the impedance of an electromagnetic sensor. Traditional fault-detection circuits sense the voltage difference developed across an open fuse, leakage current flowing through......

Input protection scheme tops other approaches:  01/06/00 EDN-Design Ideas / (added 2/06)

Inrush limiter also provides short circuit protection:  06/09/05 EDN Design Ideas  / (added 11/05)  MOSFET keeps inrush currents due to capacitive loads under control.

Isolated Driver forms Solid State Circuit Breaker:  03/03/98 EDN-Design Ideas  / (added 03/03)   -- This circuit allows standard TTL logic levels to safely drive a high-power dc load, circuit provides also overcurrent circuit breaker functionality

Isolation Barrier Precisely Protects Transducer Signals:  AN-246 - Analog Devices Application Notes  (Circuit / schematic design added 6/06) Through the Judicious Use of Isolation Amplifiers that Incorporate Transformer Coupling, You Can Design Circuits that Accurately Condition and Amplify Low-Level Transducer Signals.