I have a couple of 7805s. One is in circuit but just with a couple of filter caps on the input (still building the rest of the circuit).
The other I bread boarded with nothing but the regulator.
I connected walwart. The input on both chips measured 16.6 VDC.
On the 7805 on my circuit board I am only measuring 4.85 VDC. The bread boarded one does just a bit better at 4.9 VDC.
Both of these regulators are from the same source.
I have a third 7805 hat I got from the Shack (a 2nd source) that I have soldered up on a perf board. I am getting 5.01 VDC unloaded. That is more like I would expect.
Do I have a bad batch of 7805s from the first source?
I see from the datasheet on I'm one the low end of it's normal operating range?
The other I bread boarded with nothing but the regulator.
I connected walwart. The input on both chips measured 16.6 VDC.
On the 7805 on my circuit board I am only measuring 4.85 VDC. The bread boarded one does just a bit better at 4.9 VDC.
Both of these regulators are from the same source.
I have a third 7805 hat I got from the Shack (a 2nd source) that I have soldered up on a perf board. I am getting 5.01 VDC unloaded. That is more like I would expect.
Do I have a bad batch of 7805s from the first source?
I see from the datasheet on I'm one the low end of it's normal operating range?