INDEX

1. As I said above some breadboards will be difficult to insert IC's like 7805, LM317 etc.. due to the small sized holes.
2. I bought a new breadboard for Rs.80 in which some parts of the breadboard is not working. So you should be careful about it.
3. Some part of the breadboard may suddenly create problem. This problem will mostly eat your time. I have connected full circuit for my project and it was working properly two months ago. The ckt consist of a 7805 which convert adapter DC to 5V. Now when i switch ON power supply, the circuit is not working. On examination i found that the output voltage of 7805 is 1.1V even though input voltage to 7805 is >7.5. I was surprised to see this because i had done same ckt a month ago and no changes made in ckt. Then i used another breadboard specially for 7805 to make connections, surprisingly it is working fine giving 4.8-5V.Then i connected the output from that breadboard to my
original board where ckt was connected. It is working fine. Then I again tried in same position it is not working giving output of adapter 3-4V and output of 7805 1.1V. I doubted if the voltage regulator input is low to regulate, so i increased the adapter to 9V from 7.5(my adapter has varying voltage starting from 1.5V,3V..). Then the light of the adapter went off. Then I again increased voltage to 12V. Then also light is off. Now I decided for a new position of breadboard, where it worked properly. Then I increased voltage up to 13.5V. For all these input voltages to 7805 the input of 7805 still remained 3.5-3.7V and output .7-.8V. Finally I got a position of the breadboard where it worked
fine. The problem was of the position in the breadboard which i used.
4. One similar problem occurred when I connected LM324 with its input a variable resistor. I rotated the knob of the potentiometer( it has one end on Vcc=10v, other end on ground and middle end is connected to the LM324), the voltage output of the potentiometer is suddenly increasing from .5 to 8.8V suddenly with a small rotation of the knob. I tried to rotate shaft by connecting the middle end to another portion of the breadboard, there it worked fine. I used the same portion of the breadboard where i connected first and tried the same after removing LM324, then also it is working fine. Then i again connected LM324 in same position, still the old problem came. Then I changed the full circuit to another position of the breadboard, it worked fine.