I have a question about my project. I'm going to make a temperature-stabilizer. To make this, I think I should use a TEC with a H-bridge and a LM35. First of all, I tried to make a H-bridge by myself, I have only used four NPN transistors and It didn't go well. Then I bought L293D motor driver - not the module one, tried it and it works well. But as datasheet says, it's output current is max 600mA. But this current doesn't make TEC work efficiently. So that, I need to amplify the current. But I don't want to buy high amp motor drivers, hardwares are to expensive in my city. Of course I'll if there's no another way.
Arduino will be used to get temperature values from LM35 and give the H-bridge voltage, control the current direction when necessary. I learned how to use transistors to amplify but if I'll change the direction, it won't work. But I don't know how to make this circuit.
The algorithm that I thought using is this:
The scheme that I thought using in this:
What should I do to solve my problem? Thank you for all.