I think this double negative discussion is suitable for general consumption. I will have mine with a chicken sandwich and cold beer. But seriously, Piotrâs explanation of double negative makes meâŠsomewhat despondent or at least appreciative of the difficulty of some ESL situations.
If I say: You do not like radishes, do you? (And assuming that I am correctâŠ)
Do you say âYes I do not like radishesâ or âNo I do not like radishes.â
Americans will usually say the second. But I think many ESL speakers will say the first.
Probably because they were told that double negation means not negation so even if in their first language they will say the second trying to be correct they will say the first.
I suppose that âI donât know nothing.â you understand as âI know something.â but as I said in Polish such construction means: 'I donât know anything.".
Anything not always is replaced in Polish by our nothing. In some constructions it is replaced by our something (=coĆ).
you usage of 10nf // 100nf is somewhat redundant. I beleive you read that if you have a large capacitor (good for lower frequencies) you need to add a smaller capacitor (good for high frequencies) This is the case, however in your circuit the 2200”F is the large one and either the 10n or 100n can be the small one.
The L7805 can be used as you have shown. The âgndâ pin passes a little more current that and LM317 but I donât think it will matter in your usage. However you will not be able to control to a voltage lower than 5V where the LM317 can go down to ~1.25 volts.
The L7805 is current limited, the 1A fuse is not going to do much.
The 1n4148 is too small for the function of protecting U1, I would suggest as a minimum a 1N400x where X can be 1,2,3 or 4. This digit signifies the maximum reverse voltage of the part where 1 = 50V and 4 = 600V. Any version will be fine for your circuit.
Now the real questionsâŠ
How much current do you expect to draw? For each watt of power lost in U1 it will rise 50 °C. The MAX limit is about 150°C so:
Power = current x voltage
voltage = 12 -5 = 7 volts across U1
MAX power = (150 - 25)/50 = 2.5 Watts
Max current = 2.5W/ 7v = 350 ma.
So for us the help you build a functional device we need to know more about you usage how you plan on mounting U1 etc.
What is your 12V source? C4 is very large if you 12V is coming from a wall adapter. However may not be enough if coming from a rectified AC.
BTW: Like most of life, detail design is messy. Nothing is as easy as slap it together and it works.
Mainly to second what you say. A bunch of good advice. As I think @paulvdh mentioned there may be significant differences in 78XX 3 terminal regulators, but my experience with (probably old Motorola or maybe National Semiconductor or Fairchild) parts is that putting a resistor in the ground leg often does not work. So I would advise caution about doing this in a production design. Adding a schottky diode (maybe BAT54 or 1N5819) with anode to ground pin and cathode to regulator output might help prevent the latchup malfunction that I have seen.
If you still have questions or can point to something you are unclear about, please post it. From my side it is sometimes difficult to communicate technical characteristics with I donât know the technical foundation of the OP.
Off topic but using linear regulator like 7805 with 12V input and 1A current is not very good engineering, because the 7805 will get hot. Sauna is not for ICs.
I would use something like this (a switching type) https://www.digikey.com/en/products/detail/recom-power/R-78E5-0-0-5/2834904
There are plenty of models from different manufacturers. What I know they canât be adjusted like 7805.
And there are adjustable switching regulators, but they need more components than 7805.
Secreted pine tree rosin dissolved in alcohol (not beer) makes quite a good inert flux for soldering.
That could be the reason for @retiredfeline 's comment, unless, of course, he chews on the branches whilst swinging through the trees.
Various cats of the feline variety have been known to spend time in trees.
First stage valves in amplifiers sometimes were fitted with spring loaded shields to prevent microphony from noise or the output speaker. My dad used to say my music was noise so same thing in that case.
But seriously, Piotrâs explanation of double negative makes meâŠsomewhat despondent or at least appreciative of the difficulty of some ESL situations.
Yes, we have no bananas
