PD or Iota for my upgrade?
I'm thinking about a converter and battery upgrade. The batteries will be wet cell lead acid 6 volt Possible T-105s or the 230AH, EGC2 from Sam's club. I'll probably go for four. (Does nayone have...
Forum Discussion
Sure, the error amp is inside the Unitrode chip. But it's still accessible from the chip pins.
Unitrode 3846 Spec
Non-inverting input = pin 5
Inverting input = pin 6
Output = pin 7
Pin 1 is Current Limit Adjust. The problem could be with this circuit. I would trace what Pin 1 is connected to.
Make sure the reference voltage remains constant.
There's either a design flaw or stability/noise problems.
I've designed many dc/dc converters using PWM controllers similar to this one.
Sal
Unitrode 3846 Spec
Non-inverting input = pin 5
Inverting input = pin 6
Output = pin 7
Pin 1 is Current Limit Adjust. The problem could be with this circuit. I would trace what Pin 1 is connected to.
Make sure the reference voltage remains constant.
There's either a design flaw or stability/noise problems.
I've designed many dc/dc converters using PWM controllers similar to this one.
Sal
DryCamper11 wrote:Salvo wrote:
Go and measure your PD. Take a look at the error amp circuit.
I understand what you're suggesting, but the true "error amp" is inside the UC3846 Unitrode chip. There's nothing to look at there. There are really multiple error amps - current and voltage. They receive inputs from circuits that monitor the voltage and current.
The voltage monitoring is a pretty simple circuit, but the current monitoring is more complex. Still, it should be possible to check the inputs to the error amps in the Unitrode to see if it's getting the wrong signals from the monitoring circuits about current or voltage.
