12V LM350T Lead Acid battery charger question

[khatus]

Hello friends, I want to make this lead acid battery charger.

Here, I want to use 1000pF polyester film capacitor instead of the electrolytic capacitor C3? My first question is can I use 1000pF polyester film capacitor instead of 1000pF electrolytic capacitor?

if i use the DPDT Self-Locking Push-Button Switch, in the place of the S1 Start pushbutton, will there be any problem?

 

[betwixt]

I have no idea why electrolytic is shown in the diagram, the part is not critical and any non-polarized capacitor should work.
Pin 1 is really for internal compensation and not intended to be grounded at all but I don't think any damage will occur if a latching switch is used. I think I would try adding a resistor (100 Ohms?) in series with the switch, if it still works it would be safer. Only in series with the switch, leave the capacitor between pins 1 and 8 or it might oscillate.

Brian.

 

[khatus]

Will there be a problem if I use 15 ohm and 230 ohm 1/4 watt resistors? The value of these two resistors must be high wattage or low wattage? If it is high wattage then how much wattage should I use?

 

[danadakk]

I did a sim of grounding that pin, and sim showed no reak effect on output.
So my guess is Spice model not complete. Looks like Q9/10/12/13 off, so
output goes high allowing LM350 to function as 2A current source ? So
button must be momentary ?

Current thru R2/R3 limited by 15K R4, so low wattage should be fine.