Hi again...
I'm now building a driver box for a robot arm. My problem is about the supply of its encoders..
The encoders, of course, needed a supply for its operation, in this case its 5v. There are a total of 5 sets of these encoders (A, B, Z and Limit switch). My main supply is a 24V DC source (ALL power is taken from it {motor supply, IC supply, optocouplers, etc..}building it is part of my project), but for now, I'm using a power supply off the shelf.
As you can guess, the 24V is the input to the LM7805 which outputs 5V. I know its not very good to do that for efficiency... I only did that because I thought a SINGLE LM7805 could handle the supply for all the encoders... I was astounded when the current reading was around 0.75A.... The LM7805 went really hot. Nearly-skinned-my-finger-damn-hot.
I mean P= (24-5)*0.75=14.25 watts is NOT negligible.
I searched the net for solutions about this without considerable success.. I know something about this could be done since I'm just "copying" the design from the old design of my adviser.
I wanted to find out the components of his circuit so I can copy it (the encoder conditioning part of my project is really just an extra, its just couple of 74LS245 buffers to buffer the encoders from the external microcontroller), but there is so much wiring in the driver that to see the markings of components, I have to disassemble it. I can't disassemble it now since someone is using it and if I break it I'll make someone really mad..
I already sent an e-mail to my adviser, but for the mean time, I just want to find out help from the forum..
Can anyone suggest an alternative to the LM7805? thanks!!!!!!!
I'm now building a driver box for a robot arm. My problem is about the supply of its encoders..
The encoders, of course, needed a supply for its operation, in this case its 5v. There are a total of 5 sets of these encoders (A, B, Z and Limit switch). My main supply is a 24V DC source (ALL power is taken from it {motor supply, IC supply, optocouplers, etc..}building it is part of my project), but for now, I'm using a power supply off the shelf.
As you can guess, the 24V is the input to the LM7805 which outputs 5V. I know its not very good to do that for efficiency... I only did that because I thought a SINGLE LM7805 could handle the supply for all the encoders... I was astounded when the current reading was around 0.75A.... The LM7805 went really hot. Nearly-skinned-my-finger-damn-hot.
I mean P= (24-5)*0.75=14.25 watts is NOT negligible.
I searched the net for solutions about this without considerable success.. I know something about this could be done since I'm just "copying" the design from the old design of my adviser.
I wanted to find out the components of his circuit so I can copy it (the encoder conditioning part of my project is really just an extra, its just couple of 74LS245 buffers to buffer the encoders from the external microcontroller), but there is so much wiring in the driver that to see the markings of components, I have to disassemble it. I can't disassemble it now since someone is using it and if I break it I'll make someone really mad..
I already sent an e-mail to my adviser, but for the mean time, I just want to find out help from the forum..
Can anyone suggest an alternative to the LM7805? thanks!!!!!!!