[SOLVED] LT1513 SLA Battery Charger Simulation with LTSpice

[Dr Phibes]

Help Needed - LT1513 SLA Battery Charger Simulation with LTSpice

Hi,

This is probably a basic question, but I'm struggling to understand why (in LTSpice at least) a resistor appears to be needed upstream of the battery's positive terminal in a LT1513 circuit.

None is shown in the LT1513 datasheet, but it is included in the LT1513 test fixture, and this circuit (which is may attempt at a DC UPS with a SLA battery) appears to need it.

Image:


Any ideas? Feel free to comment on the rest of the circuit - surprisingly few references to doing this with these chips on the web.

Thanks in advance,

Lee

 

[keith1200rs]

If you mean 'why is the resistor needed to make the simulation work?' it is most likely to prevent a theoretical infinite current on power up due to a capacitor across a voltage source. That is a common cause of simulation failure when using ideal components.

Keith

 

[Dr Phibes]

If you mean 'why is the resistor needed to make the simulation work?' it is most likely to prevent a theoretical infinite current on power up due to a capacitor across a voltage source. That is a common cause of simulation failure when using ideal components.

Keith

Ah, that makes sense. Thanks very much.

Lee

 

[keith1200rs]

You can use a resistor value which doesn't affect the operation while avoiding the infinite current such as 0.001 ohms.

Are you a Vincent Price fan?

Keith