Additional RFI Protection for Line
Input Circuits: 8KB PDF
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Advanced Polarity Protection With
MOSFETs: Advanced Power
Switching and Polarity Protection for Effects
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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 |
Battery Discharge Monitor:
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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
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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 |
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 |
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 over temperature 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.
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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
over current 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....
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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. |
Electronic Fuzing:
National Semiconductor Application Notes,05-Aug-1995
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Electronic Security System:
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Handy Circuit Gives Systems Flexible
Fault Protection:
08/04/03 Electronic Design - Design Briefs / Many
applications must include a capability to
automatically disconnect power from an operating
circuit. Such applications include thermal shutdown
of high-voltage power supplies in radar and X-ray
systems, shutdown to limit inrush current during. .
. |
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 |
Home Appliance Protector:
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Hot-Swap Controller Makes Adjustable
Circuit Breaker: 11/10/03
Electronic Design - Design Briefs / Medium- and
high-voltage systems that range from 9 to 72 V often
require one or more of the following circuit
capabilities: hot-swap control, circuit-breaker
fault protection, and inrush current limiting.
Without R4, the circuit shown in .
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House Security System: |
IC Controlled Emergency Light With
Charger:
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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).... |
Over-/Under-Voltage Protection of
Electrical Appliances: |
Overload & Reverse Current Circuitry
Protects Battery & Load:
03/01/96 EDN-Design Ideas |
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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Overvoltage Protection for LM317: |
Overvoltage-tolerant quad buffer used
as voltage level shifter:
02/23/98 Electronic Design - Ideas for Design / The
LCX standard logic product family was designed with
overvoltage-tolerant inputs and outputs, enabling
users to easily interface LVTTL and 5-V TTL buses.
Because the LCX outputs are overvoltage-tolerant
when disabled, system designers can take. . . |
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:
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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. |
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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. |