What is the purpose of TIP32 here?

[dreamlover]

Hi, this is a circuit of a li-ion charger based on the principle of a crowbar. One thing I am not getting is the use of the TIP32 PNP transistor. What is the use of TIP32 and why a 1N4148 diode is connected in reverse polarity?

 

[Easy peasy]

it's a crappy shunt regulator and Q1 is the wrong way round - overall a bad ckt - do not use ...

 

[crutschow]

Don't mess around with using some unknown design charger for Li-ion batteries as they can burn or explode if improperly charged.
Use a dedicated charger, or a circuit using one of the Li-ion charger ICs designed specifically for that purpose.