Part of a project I'm working on involves lighting crackers and fireworks from the Arduino. I use a 74HCT154 to select which output I should trigger. Basically, "lighting" means sending unrestricted current from a battery to a 10ohm resistor, which, of course, instantly burns.
I can do this by just connecting an array of reed relays to the outputs of the 74HCT154, but I thought I could maybe avoid such a wirework. Since the enabled output of the 74HCT154 goes to LOW state, I thought I could use only one "general" relay to the battery, then simply sink current from the selected output through the 154.
But I haven't been able to find the maximum current it can sink without damages (For the HCT family. It's available for the HCU). The triggering involves relatively high current (I assume a 1/4W resistor will require a few watts to burn *), but during a very short amount of time (My experience with electrical detonators showed that the firework start and the circuit break were almost instantaneous)
- This leads me to another question : Is there a way to know of the maximum current a circuit used ? Common multimeters' can't do such things, since their update frequency is slow (a few measurements/second)