Hi all,
I'm building an ATX based power supply (a box with an ATX socket on the back with terminal posts on the front with breadboards on the top). Rather than reconnecting wires from each of the posts to the the four breadboard power rails to change the voltage, I was thinking of using a rotary switch (break before make) to change the voltage as shown in the left side of the attached image. If I use a 2-pole 5 position switch then I could have an LED indicate which voltage is selected.
My main question is what would be a reasonable current rating to supply a breadboard rail? I was thinking somewhere in the 0.5A - 1A range should be plenty. For 0.5A is was thinking of a switch like this: http://www.rapidonline.com/electronic-components/miniature-wafer-switch-2-x-5-50-1101. There seems to be quite a price increase for a 1A rating (although if anyone knows of any for a couple £ each then please let me know).
If I were to be doing something with motors, then I could power them from the posts rather than the rails. Can anyone think of a situation where I'd be likely to draw more than 0.5A from a single rail? There will be four rails for two 830 point boards and a 400 point board.
An alternative would be to use relays as shown in the right side of the image, but this was only if I needed currents higher than 1A, which I am starting to think is a little excessive.
Any thoughts?
I'm building an ATX based power supply (a box with an ATX socket on the back with terminal posts on the front with breadboards on the top). Rather than reconnecting wires from each of the posts to the the four breadboard power rails to change the voltage, I was thinking of using a rotary switch (break before make) to change the voltage as shown in the left side of the attached image. If I use a 2-pole 5 position switch then I could have an LED indicate which voltage is selected.
My main question is what would be a reasonable current rating to supply a breadboard rail? I was thinking somewhere in the 0.5A - 1A range should be plenty. For 0.5A is was thinking of a switch like this: http://www.rapidonline.com/electronic-components/miniature-wafer-switch-2-x-5-50-1101. There seems to be quite a price increase for a 1A rating (although if anyone knows of any for a couple £ each then please let me know).
If I were to be doing something with motors, then I could power them from the posts rather than the rails. Can anyone think of a situation where I'd be likely to draw more than 0.5A from a single rail? There will be four rails for two 830 point boards and a 400 point board.
An alternative would be to use relays as shown in the right side of the image, but this was only if I needed currents higher than 1A, which I am starting to think is a little excessive.
Any thoughts?
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