应该是电池反冲了 BATTERY RECOIL, BATTERY BACKLASH
- Thread starter Understone
- Start date
Ampster
Renewable Energy Hobbyist
I use a buck boost converter with a small screen to control voltage and current from my Meanwell power supplies. I have a variety of small 14 to 35 volt packs so that works for me.
It will blow if the battery starts trying to feed high current into the power supply. Hopefully avoiding damaging the power supply.
The issues with a diode are that you will have a 0.5-1.2V drop across it. So your inaccurate voltage read out is even more inaccurate.
That 1V drop will turn into a lot if heat if you are drawing a lot of current through it. I.e you will need a very large diode.
And the most common failure mode for a diode is short circuit which is not ideal.
A fuse doesn't have any of these issues. The only issue with a fuse is that a small amount of energy will flow back into the psu while the fuse is blowing. This is unlikely to be enough energy to damage the psu (hopefully).
Vigo
Solar Addict
In actual practice on my cheapie PSUs, the side effect of leaving the battery connected to the output has ranged from 'an led stays lit forever' to 'the cooling fan on the psu will intermittently run for no appreciable reason'. But I have yet to break one from 'leaving it hooked up'.
As far as whether or not to leave it hooked on the AC side, i HAVE blown up one of the 'inrush current limiter' thermistors on the input side. Theoretically that shouldn't happen to begin with, but if we acknowledge that it is possible for it to happen, leaving the unit hooked up to the AC source should prevent it. But you may still run into 'fan runs for no reason even though psu sits idle' and you will have some small idle draw.
As far as protecting the output, you can put a switch on the output circuit, and can even control that switch based on voltage levels etc. I've posted elsewhere about using a cheap PSU as the input to a cheap pwm SCC that has a current limiting feature, at which point you have something close to a 'real' battery charger with a ton of adjustability for ~$40 on the low end. The SCC will simply disconnect the PSU from the battery (or the negative pole of the circuit, at least) when voltage rises to the setpoint you create. You could add another device to make it disconnect the other side of the circuit too, but there would be some minor caveats. Or just use the load port of a cheap SCC to control a switching device directly between the psu and battery without making it flow through the SCC. This is just using a <$20 pwm scc as an adjustable 'voltage window switch' between two devices. I have bought adjustable voltage window switches that ARENT scc's for as little as $5 on Amazon, too.
As far as whether or not to leave it hooked on the AC side, i HAVE blown up one of the 'inrush current limiter' thermistors on the input side. Theoretically that shouldn't happen to begin with, but if we acknowledge that it is possible for it to happen, leaving the unit hooked up to the AC source should prevent it. But you may still run into 'fan runs for no reason even though psu sits idle' and you will have some small idle draw.
As far as protecting the output, you can put a switch on the output circuit, and can even control that switch based on voltage levels etc. I've posted elsewhere about using a cheap PSU as the input to a cheap pwm SCC that has a current limiting feature, at which point you have something close to a 'real' battery charger with a ton of adjustability for ~$40 on the low end. The SCC will simply disconnect the PSU from the battery (or the negative pole of the circuit, at least) when voltage rises to the setpoint you create. You could add another device to make it disconnect the other side of the circuit too, but there would be some minor caveats. Or just use the load port of a cheap SCC to control a switching device directly between the psu and battery without making it flow through the SCC. This is just using a <$20 pwm scc as an adjustable 'voltage window switch' between two devices. I have bought adjustable voltage window switches that ARENT scc's for as little as $5 on Amazon, too.
