Hi,
Recently I need to control Triac by MCU. I wonder if there exists some protection equipments to develop these kind of embedded system such as current limiting of main AC as I am just a beginner.
Thanks!
Hi,
Recently I need to control Triac by MCU. I wonder if there exists some protection equipments to develop these kind of embedded system such as current limiting of main AC as I am just a beginner.
Thanks!
Put a toaster, electric iron or room heater in series with your device. It will limit current to a level that the mains fuse would not blow.
Use a variable transformer (variac) to ramp up the voltage slowly, so you have time to switch the circuit off when things start smoking
Use an insulation transformer to avoid having all your equipment connected to the mains.
Wim
You can put a light bulb in series with the circuit.
BUT the most important thing is to use an isolation transformer! This is at no time more important than if your circuit does not have isolation itself. You leave both sides of the AC power on the other side of the isolation transformer floating wrt ground. Otherwise a single point fault can take out your circuit, any emulators and other expensive equipment that you're using, and perhaps even computers that are connected to it. It could also give you a nasty (perhaps fatal) shock much more easily.
Best regards, Spehro Pefhany
-- "it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com
Use optical isolators (or isolating triac) to isolate the AC from the MCU. Run the MCU off a wall-wart.
-- Keith
In article , Wim Ton writes
Use a transformer to run the circuit at 24V ac until you are confident the design is OK. The triac will work the same at the lower voltage.
-- Tim Mitchell
I usualy rely on my wits to protect me although i have learned the hard way to clearly mark any mains plugs/leads used to conect the equipment under test to the mains
as other posts have sugested bulbs in series etc also variac and isolation transformer of course. dont forget that about only a mere 20ma at mains voltage is considered enough to be hazardous to health.
fusible resistors can also be a help as they initialy limit the curent and also disconect it (any metal film resistor will fuse at high overload, puting a sleave over it wil stop bits hiting you in the face when it explodes) you can also get re setable curent trip devices.
other personal safety devices often get tripped far too easily if you have much in the way of interfence supresion or scopes conected to it etc.
Colin =^.^=
The triac may work the same at the lower voltage. There are a number of issues that might bite you and make it not. It's a good idea first, as it's unlikely that if it doesn't work on 24V, it won't work on 100/120/240/415/...
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