Questions tagged [fail-safe]
The fail-safe tag has no usage guidance.
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How to design/build a relay-triggered "crowbar" circuit?
(This is a continuation of Failsafe for relay contact welding.)
I'm trying to wrap my head around something like a "crowbar" circuit, only, instead of tripping on over-voltage, it should ...
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Failsafe for relay contact welding
So, I'm fiddling with a design for a widget, and one of the "fun" parts is to ensure that power is reliably cut without human intervention. Power is normally controlled by relays, which have ...
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How can I detect a power failure on a 120V circuit and activate a battery-powered indicator light?
I recently got a new septic system installed. It's a Presby/mound system whereas our old system was gravity fed to a single tank with fingers. The mound system has a pump tank and the tank is wired on ...
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Failsafe circuit for a bistable latching solenoid
I am new to embedded circuits and working on a problem with which I need help.
I am using ESP32 soc for controlling a bistable valve using DRV8833 driver module. Please refer to this link for valve ...
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Dual NMOS as AC switch
I would like to preface this by saying that my project here is an educational exercise, and I hope that by sharing it and requesting feedback, some other fine folks will learn from it too.
I know that ...
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Fail-safe half-bridge
I've been thinking about this for a while now, to use in the powered jaw of some publicly accessible, human-sized animatronics. I want a lot of force to be available to move quickly, and to ...
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When the power goes off, a line must be grounded - how?
I need a line to be grounded as power to a board is failing. Complicating the issue is the fact that this line is critical to circuit operation and cannot tolerate even nanoVolts of additional noise ...
- 13.2k
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Intentionally tripping a fuse to disable a circuit in an unrecoverable fault condition?
I'm building a device that regulates the atmospheric composition of a space using a gas sensor and a control loop to actuate a solenoid valve to release compressed gas into the space. Due to the ...
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Is there such a thing as a fail-safe, low-power relay?
Background
Let's say I have a device. I can't give details, but, like many heat-producing devices, it's intended to be used for a limited period of time, but if left on indefinitely can be very ...
- 289
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Turning a circuit off using a 240v signal
I have a home-built controller for a HERMS brewing system (Heat Exchanging Recirculating Mash System). The purpose of this controller is to drive liquid (wort) from a large mashing vessel (a cooler ...
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Use attiny as an external watchout timer
I like to failsafe an Atmega8 mcu despite having its own WDT. does it make sense that if I add an attiny to the circuit to check if each loop is taking a specific time, if not reset the Atmega chip?
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Manual overriding a DC-motor with H-bridge
I have created the following circuit where I use a VNH7070BASTR full bridge motor driver to control a DC-motor. The goal is to open and close a drawer using a rack and pinion system. A new requirement ...
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Opening fail-safe electrical strike door with a spring
I have a 12V fail-safe electrical strike currently installed and working on a door, but I want it to open slightly when it is powered down, but a spring apparently won't do as my strikes keep themself ...
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Fail-safe joystick connection
I am looking for ideas to implement fail-safe function in joystick control box. At present, the 5V joystick HF11S10 is connected to STM32 ADC inputs via simple 5.1k:9.1k divider. We are revising the ...
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