Tickled_Pink
New Member
I've just started tinkering about with electronics and have a question regarding the 7404 Hex Inverter. I've put together a very simple circuit to test the output from a 7404.
The 7404, as everyone here will know, has a Ground pin. I have pin 2 connected to the anode of the LED. Pin 1 is connected to one of the joystick lines (which can be changed to output). However, if I connect the Ground pin to the Ground rail, the chip seems to bypass all the power to the rail and the LED fails to light.
When I disconnect the gnd pin, everything seems to work ok. I'm just wondering if there'll be any damage to the chip by doing this as the 7404 seems to need to have the Vcc connected (unlike other logic devices) - obviously to provide power to the outputs when the inputs are logic 0.
FYI: The board is being powered by the joystick port on an Atari 800XL computer.
The 7404, as everyone here will know, has a Ground pin. I have pin 2 connected to the anode of the LED. Pin 1 is connected to one of the joystick lines (which can be changed to output). However, if I connect the Ground pin to the Ground rail, the chip seems to bypass all the power to the rail and the LED fails to light.
When I disconnect the gnd pin, everything seems to work ok. I'm just wondering if there'll be any damage to the chip by doing this as the 7404 seems to need to have the Vcc connected (unlike other logic devices) - obviously to provide power to the outputs when the inputs are logic 0.
FYI: The board is being powered by the joystick port on an Atari 800XL computer.