speedEC
Full Member level 6

Dear All,
I have made a high/low voltage monitor circuit for my 6v, 4.2Ah lead acid battery using LM358 IC. I have used 3.3v zener - resistor for reference voltage and connected to Inverting Pin. Battery voltage connected to Non-Inverting pin thro' 100K potentiometer. I know that if Voltage at Non-Inverting goes above Inverting Pin, then Output will be High and vice-versa. Also the circuit works. But, I don't know whether it shows correctly or have I not fully understand the concept. Bcoz, If I set reference voltage using 3.3v zener, it always stays constant at 3.3v even if there is any changes in voltage. If so, if the battery voltage is above 3.3v, the LED will be lit for HIGH Voltage. Also, If I goes down below 3.3v, The low voltage LED lit. Is this correct? How can I set 6.9v as HIGH VOLTAGE and 5.5v as LOW VOLTAGE? I am very much confused.
Urgent help pl.
thanks
pmk
I have made a high/low voltage monitor circuit for my 6v, 4.2Ah lead acid battery using LM358 IC. I have used 3.3v zener - resistor for reference voltage and connected to Inverting Pin. Battery voltage connected to Non-Inverting pin thro' 100K potentiometer. I know that if Voltage at Non-Inverting goes above Inverting Pin, then Output will be High and vice-versa. Also the circuit works. But, I don't know whether it shows correctly or have I not fully understand the concept. Bcoz, If I set reference voltage using 3.3v zener, it always stays constant at 3.3v even if there is any changes in voltage. If so, if the battery voltage is above 3.3v, the LED will be lit for HIGH Voltage. Also, If I goes down below 3.3v, The low voltage LED lit. Is this correct? How can I set 6.9v as HIGH VOLTAGE and 5.5v as LOW VOLTAGE? I am very much confused.
Urgent help pl.
thanks
pmk