How to regulate voltage using TIP122

Thread Starter

kithul godage Vijitha

Joined Aug 8, 2017
7
Need regulation accuracy, maximum current, maximum input voltage.
What does it do below 14v?
actually I hope to use this to Alternator, for charge the lead acid batteries. then 200Ah batteries are connect as parallel so I want to charge the batteries without over charging. because I want regulate alternator output, using TIP122.
 

Thread Starter

kithul godage Vijitha

Joined Aug 8, 2017
7
How is the input V/I?
How is the Vout?
actually I hope to use this to Alternator, for charge the lead acid batteries. then 200Ah batteries are connect as parallel so I want to charge the batteries without over charging. because I want regulate alternator output, using TIP122.

Input voltage is not constant value. it will change according to RPM of alternator. maximum current 80A.
 

cmartinez

Joined Jan 17, 2007
8,220
actually I hope to use this to Alternator, for charge the lead acid batteries. then 200Ah batteries are connect as parallel so I want to charge the batteries without over charging. because I want regulate alternator output, using TIP122.

Input voltage is not constant value. it will change according to RPM of alternator. maximum current 80A.
How many TIP122 do you have with you? Because a single of those transistors is only capable of handling 5A at most. And that's under ideal conditions. You'd end up with a rather inefficient circuit with numerous components to accomplish what you want.

There are other options out there, such as MOSFETS. Is the use of TIP122 for your application a must?
 
Last edited:

ScottWang

Joined Aug 23, 2012
7,397
actually I hope to use this to Alternator, for charge the lead acid batteries. then 200Ah batteries are connect as parallel so I want to charge the batteries without over charging. because I want regulate alternator output, using TIP122.

Input voltage is not constant value. it will change according to RPM of alternator. maximum current 80A.
The circuit can't be that simple, because you want to build the batteries charger with high current.
 

Thread Starter

kithul godage Vijitha

Joined Aug 8, 2017
7
The circuit can't be that simple, because you want to build the batteries charger with high current.
How many TIP122 do you have with you? Because a single of those transistors is only capable of handling 5A at most. And that's under ideal conditions. You'd end up with a rather inefficient circuit with numerous components to accomplish what you want.

There are other options out there, such as MOSFETS. Is the use of TIP122 for your application a must?
it doesn't matter. I want to just create a circuit for apply Alternator. I haven't idea how to use MOSFET for regulate the voltage. please send me your idea. It will more helpful to me.
 

ScottWang

Joined Aug 23, 2012
7,397
Voltage regulator for Alternator:

Vin = input voltage unknown (range?).
Iin = input current 80A.
Vout = input voltage unknown (14V?).
Iout max = 80A * eff% = ? A (80A?)

12V Batteries:

Iout max = 200Ah
Vout = 14V
 

dl324

Joined Mar 30, 2015
16,846
actually I hope to use this to Alternator, for charge the lead acid batteries. then 200Ah batteries are connect as parallel so I want to charge the batteries without over charging. because I want regulate alternator output, using TIP122.
14V is not optimum for charging 12V lead acid batteries, nor is charging them in parallel.

Go to batteryuniversity.com and study the requirements before you try to build a charger. You'll find that you need a timer and multiple voltages.
 
Top