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I ordered a kit that is missing its 78L05. Can I substitute a 7805, or would I need to also adjust the cap values? Here is the entire schematic.

Here is the voltage regulation portion of the schematic:

enter image description here

I have emailed Bleep Labs, but I thought this forum might be faster.

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Yes, you should be able to substitute a 7805 for the 78L05 if you are willing to do a little kludging mechanically. The L version is physically smaller and can dissipate less power and may be rated for less current. If this is just a one-off, go ahead and solder on a 7805 in a TO-220 package onto the pads intended for the 78L05.

By the way, that must be a very old design. 10 nF is rather skimpy for the the input and output caps. Nowadays you can easily put a small 10 µF cap on the output, and at least a 1 µF on the input depending on what the input voltage is.

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  • \$\begingroup\$ I guess they are 100nF capacitors and there is a typo. \$\endgroup\$ Mar 16 '12 at 15:22
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    \$\begingroup\$ Thank you, Olin. I am worried about the larger package -- I started placing things last night and could barely insert the electrolytic caps' legs. :\ \$\endgroup\$ Mar 16 '12 at 15:32
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    \$\begingroup\$ @abdullahkahraman: that wouldn't surprise me, unfortunately. \$\endgroup\$ Mar 16 '12 at 15:33
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The 78L05 data sheet recommends a 330 nF on the input and a 10 nF on the output.

For the 7805 a 330 nF is recommended on the input and a 100 nF on the output.

Ceramics would be suitable.

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