Advanced Polarity Protection With MOSFETs:
Advanced Power Switching and Polarity Protection for
Effects |
Amplifier Thermal Protection:
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Audio Amp Output Power Limiter:
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Audio Level Control Device: compressor circuit
based on LED and photodiode |
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Battery Discharge Monitor: |
BatteryProtection Circuit Allows Surges:
06/05/97 EDN-Design Ideas / Circuit monitors two
lithium-ion batteries and protects both of them
against Overcharging, Overdischarging, and
undervoltage |
Circuit Breaker has Programmable Delay: 01/16/97
EDN-Design Ideas / This circuit provides overload
and short-circuit protection to a5V power-supply
output |
Circuit Detects & Disconnects Overvoltages:
04/25/96 EDN-Design Ideas |
Circuit Ensures Safety in Poweron operation:
04/24/03 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit |
Circuit folds back current during fault conditions:
11/28/2002 EDN - Design Ideas / You can use
monolithic linear regulators at currents lower than
5A for most applications. Most manufacturers of
these devices integrate current-limiting and thermal
shutdown to prevent damage during fault conditions.
For currents greater than 5A, most linear supplies
use controllers that allow the user to select the
pass element to handle different current
requirements |
Circuit guards Against Battery Reversal:
07/06/95 EDN-Design Ideas |
Circuit Prevents Deep Discharge of Batteries:
09/26/96 EDN-Design Ideas / To avoid the deep
discharge that can destroy or shorten the life of a
rechargeable battery, you must disconnect its load
before the discharge is complete
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Circuit Protects Against AC Line Disturbances:
07/29/98 EDN-Design Ideas / operates by switching
off the power supply upon detection of undervoltage
or overvoltage conditions
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Circuit Protects Battery From Overdischarge:
04/12/01 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find the one of interest / In
some applications, it is undesirable to
Overdischarge the battery, because it could
irreversibly reduce the batterys capacity and the
number of discharge/charge cycles. This circuit
protects a single NiMH (nickel-metal-hydride) cell
by disconnecting the load from the battery when it
gets discharged enough. |
Circuit protects bus from 5V swings: 11/14/2002
EDN - Design Ideas / The circuit in Figure 1
automatically detects voltage and protects a bus,
such as a 3.3V-limited PCI bus, from 5V signal-level
swings. You can also use the circuit to determine
bus-voltage swings within one bus-cycle for setting
appropriate termination voltages of protection
diodes or termination resistors.. |
Circuit Protects Computer's Input: 05/26/94 EDN-Design
Ideas |
Circuit Protects FPGAs From killer Spikes :
04/23/98 EDN-Design Ideas |
Circuit protects system from overheating:
11/08/2001 EDN - Design Ideas / The two-chip circuit
in Figure 1 provides fan control and overtemperature
warning and shutdown signals to protect systems from
excessive heat. The circuit monitors the temperature
of the pc board and the die temperature of a CPU, an
FPGA, or another IC with an on-chip
temperature-sensing transistor. . |
Circuit Provides Flexible gain Ranges: 06/21/01
EDN-Design Ideas / PDF contains multiple circuits -
scroll to find this circuit.
|
Current Limiter Provides Latch up Signal:
01/01/98 EDN-Design Ideas / Current-limiting circuit
both signals a latch-up condition and prevents
latch-up-induced overcurrent destruction of a CMOS
IC or group of ICs |
DC Fault Protection Circuit for Audio Amplifiers:
Circuit ideas how to replace traditional CD
protection relays with MOSFETs |
Dual comparator thermally protects lithium ion
battery : 09/18/03 EDN-Design Ideas / Most
manufacturers recommend that you don't change
lithium-ion batteries at temperatures lower than 0�C
or higher than 50�C. You can monitor both thresholds
by adding a thermistor and dual (window) comparator
to a lithium-ion battery charger (Figure 1). Set the
low-temperature trip point at 2....
|
Electronic Fuse Emulates Fast or Slow Blow Fuses:
11/09/00 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find the one of interest / The
electronic-fuse circuit in this article 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.
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Electronic Fuzing: National Semiconductor
Application Notes,05-Aug-1995 |
High side driver has fault protection:
09/05/2002 EDN - Design Ideas / 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 |
Isolated Driver Forms Solid State Circuit Breaker:
03/03/98 EDN-Design Ideas |
Logic PSU With Overvoltage Protection: 5 volt
regulated power supply for TTL and 74LS series
integrated circuits, includes output Overvoltage
fault protection |
Loudspeaker Protection & Muting:
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MOSFET Beats Murphy's Law: 12/22/94 EDN-Design
Ideas |
Open collector output provides fail safe operation
: 09/04/03 EDN-Design Ideas / It is common
practice to use digital open-collector outputs for
control units in industrial applications. Using
these outputs, you can switch loads, such as relays,
lamps, solenoids, and heaters. One possible problem
inherent to this type of output stage is a short
circuit from the output to the supply voltage
(often, 24V).... |
Overload & Reverse Current Circuitry Protects
Battery & Load: 03/01/96 EDN-Design Ideas
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Overvoltage Protection for LM317:
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Overvoltage Protection: describes crowbar
technique that provides a useful defense for fast
Over voltage spikes and transients that could cause
damage to more sensitive components
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Polarity protector out performs Schottky diodes:
02/06/03 EDN-Design Ideas / The polarity-protection
circuit in Figure 1 is a high-performance
alternative to the usual series diode (often
Schottky). The circuit incurs a much lower voltage
drop than even the best Schottky diode. The circuit
uses MOSFET devices because of their low
on-resistance. For the transistors in this design,
the combined on-resistance is 0... |
Power line outage flashes red alert: 06/13/2002
EDN - Design Ideas / This Design Idea expands on a
circuit in a previous one to configure a
power-outage detector with a flashing alarm (Figure
1, Reference 1). The circuit plugs into a mains
outlet and uses trickle-charged nickel-cadmium
batteries. The green-LED monitors the presence of
line voltage. The BZV55-C4V3 zener diode, D1
protects the batteries against overvoltage.. |
POWER SUPPLY FAILURE ALARM: This circuit employs
an electrolytic capacitor to store adequate charge,
to feed power to the alarm circuit, which sounds an
alarm for a reasonable duration when the supply
fails. |
Protection Circuit Covers a Wide Range: 07/17/97
EDN-Design Ideas / |
Protection for your Electrical Appliances: The
simple circuit given here switches off the mains
supply to the load as soon as the power trips. The
supply can be resumed only by manual intervention.
Thus, the supply may be switched on only after it
has stabilised. |
RS232 Overvoltage Protection Circuits: |
Safety device uses GMR sensor: 07/10/03 EDN-Design
Ideas / This Design Idea presents a differential
safety device to prevent risks arising from current
leakages in household applications. The proposed
circuit uses a new method for differential current
sensing (Figure 1). The method entails the use of
Helmholtz coils and a magnetic sensor based on the
GMR (giant-magnetoresistive) effect.... |
Spark gaps Provide ESD Protection: 09/01/97 EDN-Design
Ideas |
Speaker Protector: |
Supervisory IC Protects System Against Overvoltage
Conditions : 05/13/02 Electronic Design - Ideas
for Design / Careful design limits overvoltage on
the supply input of integrated circuits, and avoids
compromising an IC's specifications. Overvoltage
damage can cause an immediate failure, or accelerate
an early-life reliability failure. Older technology
CMOS... |
Thermal switches provide circuit disconnect :
09/04/03 EDN-Design Ideas / A single temperature
sensor can provide an interrupt to a microcontroller
when the measured temperature goes out of range. You
need multiple temperature sensors when you have to
monitor more than one hot spot. A microcontroller
implements the proper protective action when one of
the temperature monitors detects an overtemperature
condition....
|
Transistors offer thermal protection for controller:
07/19/2001 EDN - Design Ideas / When a switch-mode
power-supply controller, such as On Semiconductor's
NCP1200, operates at a high ambient temperature, you
should protect the entire power supply against
lethal thermal runaway. The NCP1200 operates
directly from the power mains without an auxiliary
winding; therefore, the die in the IC dissipates
power (Figure 1).. |
Two buttons provide safe start: 07/06/00 EDN-Design
Ideas / - This circuit provides a safety interlock
that checks the actuation of two pushbuttons before
enabling a relay. When you push both buttons, the
circuit actuates the relay. At that point, you can
release one of the switches without the relays
switching off. The circuit was intended to lock out
the engine of an underwater propulsion unit. |