My circuit (a boost converter with voltage gain 4) works fine with a 9V 0.5Ah battery. But as soon as I connect my 12V 1.2Ah battery to the breadboard, the particular hole at which the positive lead of the battery goes begins to burn. Why does this happen?

 

Too much current.

Show a schematic of what's on the breadboard.

 

Too much current.

Show a schematic of what's on the breadboard.

 

What is the resistance of L1?
What is the value of R?
How is the MOSFET being driven?
What is the part number of the MOSFET?
What is the component in parallel with D1 and D2?

 

What is the resistance of L1?
What is the value of R?
How is the MOSFET being driven?
What is the part number of the MOSFET?
What is the component in parallel with D1 and D2?

R=1k
MOSFET is a logic driven power MOSFET triggered by a programmed arduino with switching f =100 kHz (IRL series)
L=100uH, 2A
C= 33 uF, 50V
I am also adding an LC filter as shown above. (The above is the complete circuit I am using)
with L=26 uH, 2A
C=10uF,16V

 

Where is the feedback circuitry to control the output voltage?

What is the drive capability (current sourcing), and voltage swing of the Arduino?

Without a snubber diode, the MOSFET is at risk.

 

Where is the feedback circuitry to control the output voltage?

What is the drive capability (current sourcing), and voltage swing of the Arduino?

Without a snubber diode, the MOSFET is at risk.

The above is an image of the actual hardware implementation. Its working with the 9V 0.5Ah battery. The 12 V 1.2Ah battery is placed above this. When this 12V battery is connected, the very next second, the positive terminal begins to burn. I am using a UNO3 Arduino. Basically I require a high voltage low current output. (Enough to light few LED lamps in series). I don't understand about feedback circuit and snubber network. It is not in my schematic diagram. This is my first hardware project. Hence I don't have much experience with hardware

 

Maximum voltage from the Arduino is 5VDC. Maximum pin source current is 40mA. There is a total current drawn limitation of 200mA for the entire board.

It is unlikely that you could light more than one or two LEDs in series without some sort of driver. Maybe as simple as a transistor.

 

Maximum voltage from the Arduino is 5VDC. Maximum pin source current is 40mA. There is a total current drawn limitation of 200mA for the entire board.

It is unlikely that you could light more than one or two LEDs in series without some sort of driver. Maybe as simple as a transistor.

When I measured current at input side (placed in series next to the battery), it was around 0.18A. Also the data sheet of my MOSFET shows
"VGS = 4.5V, ID = 32A". So the MOSFET can handle 32A current right? Or should I go for a power MOSFET with a drive circuit? Can a power MOSFET be programmed to give 67% Duty cycle at 100KHz frequency using an Arduino board? Any suggestions (I was expecting to light some 10 LEDs!)

 

The power supply input to the Arduino is a horse of a different color (that is, its specifications are different than the output pins).

An Arduino itself takes about 150mA to run. Anything attached (like LEDs) will require additional current. Commonly, estimate current draw of the Arduino at 200mA (or 0.2A).

I don't think you need 32A for 10 LEDs. On the LED datasheet, what does it say the current draw is?

 

The power supply input to the Arduino is a horse of a different color (that is, its specifications are different than the output pins).

An Arduino itself takes about 150mA to run. Anything attached (like LEDs) will require additional current. Commonly, estimate current draw of the Arduino at 200mA (or 0.2A).

I don't think you need 32A for 10 LEDs. On the LED datasheet, what does it say the current draw is?

An LED requires just 3V, 30mA. But now my board has a limitation of 200mA input. So when I boost the voltage 4 times, my current would decrease accordingly, power being constant. This is my problem.

 

Ok, stop and think about if what you just said makes any sense.

How does voltage divide in a series circuit? In a parallel circuit? Same questions, but this time ask them about current?

In a series circuit of 10 of these LEDs, you will still only need 30mA of current. The Arduino can do that. But you will need 30V. Uh oh, that's greater than 5V max of the Arduino.

So how do you switch 30V and 30mA with 5V? I'm not as familiar with MOSFETs as you, so I am sure you can come up with an answer. I'd use an NPN BJT.

 

Ok, stop and think about if what you just said makes any sense.

How does voltage divide in a series circuit? In a parallel circuit? Same questions, but this time ask them about current?

In a series circuit of 10 of these LEDs, you will still only need 30mA of current. The Arduino can do that. But you will need 30V. Uh oh, that's greater than 5V max of the Arduino.

So how do you switch 30V and 30mA with 5V? I'm not as familiar with MOSFETs as you, so I am sure you can come up with an answer. I'd use an NPN BJT.

Oops yeah, in series current is constant. Well, I am not familiar with MOSFETs either. But as you can see from the pic, I am getting an output of 19V with a 5V input (Its a 9V battery thats discharged to a state as giving just 5V or 6V). I'll try your BJT suggestion as well .

 

With only 5 V drive, might need a logic level FET, something like a FDD6530A, 20V, 21A, SM LL.