MikeML was nice enough to provide the TL431CP circuit below. It is intended to regulate the output of a solar panel to charge a 12V SLA battery.
I finally got everything shipped in and wired up but it is not working.
I checked everything over a couple of times and I am pretty sure I have everything hooked up right.
The best I am getting is .9 V. I am getting this with a battery for a load and no load.
If I disconnect the MOSFET and measure my voltage at the cathode of U1, as I change the input voltage from 2.5 volts, the voltage on the cathode changes until around 13.2V is reached, then the voltage drops to 2 volts.
I assume this is normal? The diode is turning on at this point?
I guess maybe I really don't understand the whole circuit here. What is really confusing is how my unregulated voltage is on the same bus as the regulated voltage.
Can someone please help me understand what is going on here and help to troubleshoot this circuit?
Note: for the FET, I am using a SPP18P06P.
One other note: I noticed that R1 gets a bit warm. Is this normal?
I finally got everything shipped in and wired up but it is not working.
I checked everything over a couple of times and I am pretty sure I have everything hooked up right.
The best I am getting is .9 V. I am getting this with a battery for a load and no load.
If I disconnect the MOSFET and measure my voltage at the cathode of U1, as I change the input voltage from 2.5 volts, the voltage on the cathode changes until around 13.2V is reached, then the voltage drops to 2 volts.
I assume this is normal? The diode is turning on at this point?
I guess maybe I really don't understand the whole circuit here. What is really confusing is how my unregulated voltage is on the same bus as the regulated voltage.
Can someone please help me understand what is going on here and help to troubleshoot this circuit?
Note: for the FET, I am using a SPP18P06P.
One other note: I noticed that R1 gets a bit warm. Is this normal?