I found myself in need of an inductor with low inductance and high current capabilities. Most bigger inductors like the one below do have a big core but far to much windings causing the saturation current to be fairly low.
For the last one and a half year I have been trying to design a MPPT controller for my solar panels. Most of the time has gone in to learning electronics and especially mosfets, mosfet drivers and inductors have proven to be a tough subject to grasp.
I will show you my latest attempt at mastering this project.
I will show you how I create a DC motor controller. It will allow me to change the speed and direction of the motor.
This drawing here shows you the basic structure of the project. The potentiometer controls the PWM generator to change the duty cycle. This signal then goes to a h-bridge made of two IR2110 mosfet drivers and four mosfets. The switch controls which combination of mosfets get the PWM signal and by doing so determines the direction of the motors rotation.
I will build a charge-pump on a breadboard and explain along the way, stupid mistakes included!
I simulated an OpAmp based oscillator in everycircuit.com and then build it on a breadboard to test it.
The first op amp circuit will be a square wave generator. A side-effect of this circuit is a triangle wave signal on the negative input.
The second opamp will combine this triangel wave signal with a voltage from a potentiometer into a PWM signal.
Being able to measure voltages automatically with a micro-controller is a very useful feature. Although the ADC on a micro-controller is limited to measure between 0V and 5V, this range can be extended quite easily using a special type of resistor network called a resistor divider.
In this tutorial I will be explaining how to read a voltage on an Arduino into an integer and how to convert that to a voltage. In future tutorials I will show you how to expand or narrow this measuring range.
Power mosfets are difficult to drive properly when on the high side, this is because the voltage of the mosfets drain is floating, meaning not on a fixed voltage. In this tutorial I will use the IR2110 as a dedicated high side gate driver for my mosfet, which will be switching a +12V car light. An Arduino with a simple blink sketch will provide the switching logic for the circuit.
IR2125 mosfet driver
The IR2125 driver is a simpler IC than the IR2110 dual channel high side low side driver. If you only need to switch a single high side mosfet than this is your IC of choice even though it is a bit more expensive because of it’s lesser popularity.
- The IR2110 comes in both DIP and SOIC packages.
- One high side channel. You can switch any side of a load, high, low, in the middle, its al good.
- One low side channel. You can switch the ground side of a load.
- Channels are independent. Also, you can use a single channel and ignore the other.
- High side maximum voltage of 500.
- Mosfet gate voltage between 10 and 20. Choose a mosfet that matches this. Also, you must provide this voltage to the IR2110.
- Can understand logic between 3.3V and 20V. Connect directly to your Arduino, Atmel or PIC. You must provide your logic voltage source to the chip so it knows what to expect.
- Can switch ON and OFF at maximum frequency of 5Mhz. This is more than 50 times faster than an Arduino can do PWM.
Microcontrollers like the ATMEGA’s found on Arduino’s have an ADC on board that can measure voltages from 0V up to 5V and return that as a number ranging from 0-1023. But what to do when we want to measure outside of this range?