Case# we have 13.5v Battery and we want the low voltage cut off point to be set at 10v. Can we achieve this simply by using zener diode...? If yes, then how...?
Thanks appreciates your response. Battery current is around 20A to 30A, depending on load. we have portable PV system with 50Ah battery.Zener diodes have a wide voltage tolerance which makes them problematic if you want an accurate cutoff voltage.
Better to use a precision reference, such as a TL431.
But 10V is generally to low for a 12V battery cutoff.
How much current is the battery providing?
No, this wont work.Case# we have 13.5v Battery and we want the low voltage cut off point to be set at 10v. Can we achieve this simply by using zener diode...? If yes, then how...?
Just asking, and it's okay to say "no", but did you read through any of the other responses?No, this wont work.
You can set a reference voltage with a Zener. And you will need to compare the battery voltage with this reference. In your case, the reference itself is the battery voltage at the cutoff.
The right way is to set a lower reference voltage, say 9 volts and compare the 9/10ths battery voltage with this.
Comparing will need a Comparator with Hysteresis to avoid the "Grey range" when the comparator cannot make up its mind and keeps "chattering".
You can put the zener in series with a relay to do the job, but the Grey Range will increase and the relay will "chatter"
Better use voltage reference and op amp circuit. It will be highly accurate and you can build hysteresis into it. Internet is full of circuit examples. Like this: http://www.high-voltage-lab.com/263/low-voltage-alarmCase# we have 13.5v Battery and we want the low voltage cut off point to be set at 10v. Can we achieve this simply by using zener diode...? If yes, then how...?
In our case, the portable PV system is 300Watt and Battery = 13.5V (50AH) and I want cut off point to be set at 10V.If You want to build your own Circuit,
this one will allow You to adjust the Cut-Off-Voltage anywhere You like.
And, it has a delayed action to prevent a false shut-down when
a heavy Current Load starts up.
It also doubles as a Main-Power-Switch.
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View attachment 245375
Battery will be powering 12v DC fans + 12v DC bulbs. Current drawn from battery is upto 20A. This switch will be used between load and battery, to protect battery from completely discharging.It occurred to me that You didn't state exactly how or where this Switch would be used.
You stated that You have a "300-Watt-System",
but You did not say what the Battery was powering,
and how much Current may be demanded from the Battery, or
whether You are using the Switch to separate the Battery from the PV-Panels.
This Switch will not prevent reverse Current flow.
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I Tried to simulate this one. Its cut off voltage can't be adjusted by the 10k variable resistor as it cut off every input voltage below 13.5V. It work normally at and above 13.5v.If You want to build your own Circuit,
this one will allow You to adjust the Cut-Off-Voltage anywhere You like.
And, it has a delayed action to prevent a false shut-down when
a heavy Current Load starts up.
It also doubles as a Main-Power-Switch.
.
.
.
View attachment 245375