3 sets of 20 LEDs. Each set with own switch. 4 rows of 5 LEDs in series. Each row with 1 56ohm 1/4 resistor. 9v battery to run whole circuit.
See images for circuit layout.
The aim is to be able to have each set of 20 LEDs switched on or off. Each set independently.
All LEDs are 5mm (basic 5mm ones from Jaycar).
When I power on the circuit the LEDs first in the series from the resistor end blow. The battery also gets very hot.
Can anyone give any advice? Should I be using different sizes resistors?

 

Hello,

What are the specs of the leds?
What kind of battery are you using?
If it is a PP3 9 volts battery, it is not capable of powering that many leds and will get hot due to its internal resistance.
https://en.wikipedia.org/wiki/List_of_battery_sizes

Bertus

 

Hello,

What are the specs of the leds?
What kind of battery are you using?
If it is a PP3 9 volts battery, it is not capable of powering that many leds and will get hot due to its internal resistance.
https://en.wikipedia.org/wiki/List_of_battery_sizes

Bertus

5mm LED 8mCd Round Diffused.
Yes using a PP3 9v.
What size battery/s would you recommend? Or would I need a more advanced circuit design with capacitors?

 

Hello,

Do you mean this one?
https://www.jaycar.com.au/red-5mm-led-8mcd-round-diffused/p/ZD0150
This smaller one will give you 5 times more light:
https://www.jaycar.com.au/red-3mm-led-40mcd-round-diffused/p/ZD0100
If you want to power that many leds, better use a bigger size battery.
A block with AA will already be better, but even then the time will be limited.
A block with D will give you much more power.

Bertus

 

Assuming a Vf of 2, each string will pull almost 18 mA (1/56). In total, that's about a quarter amp from a battery that can deliver 400 mAh. Not recommended. Not sure why you are blowing LEDs though. Are you sure you have it wired the way the schematic shows?

 

Most likely the internal resistance is protecting the LEDs.