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Looking to drop 6 volts dc to 4.5 volts dc

Sigh! Yes, that's true. But I routinely use one or two diodes, depending upon current, to drop my 6Vdc battery down to a nominal 5Vdc that my circuits use. It works. What can I say? It's a cheap and dirty way of doing it for home projects.

For example, I have a circuit which nominally draws 50ma during operation. Upon the needs of the project, a 200mA pulse (100mS) drives a latching relay. If I used a 20 ohm resistor to drop the voltage to 5Vdc during norminal operation, it would really screw up the circuit during the pulse as the series resistor would drop the voltage by 4V!

So, tell me, how many components would you use to drop your 6Vdc to 5Vdc?

Al

Reply to
Al
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What someone else would use is irrelevant. You use whatever you want to meet the circuit requirements. Here's a possibility for your pulsed 200 mA. Substitute whatever you're using in place of the switch.

/ +6 ----+-----o o--------+ | | [20R] [5R] | | [50 mA Load] [200 mA Load] | | Gnd ---+----------------+

For the LED circuit that was discussed a resistor is fine. For something that requires regulated 5, you can use an LDO like

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For something like a 4.5V toy motor, your diodes may be fine.

Ed

Reply to
ehsjr

You are correct!

I was just using the 200mA load situation just to show how a resistor would not do the job. And, one should use what works in their particular situation.

I've always wondered why the industry settled on 5 volts as the standard for TTL esp. since 6 volt batteries were so common. In the 60's I actually worked on a logic system which did use +6 and -6 volts for the logic. I can't remember if +6 was a one and -6 was a zero, or was it visa versa? For experimentation with this logic type, we actually used 6 volt lead/acid batteries for power. We quickly learned never to short anything here!

Al

Reply to
Al

When I did my electronics training in mid-70's, I can recall a cct that was part positive logic (1=-5V, 0=+5V) and part negative logic (1=+5V,

0=0V).

Just a little confusing.

Daniel

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Reply to
Daniel

If I understand your question correctly, most people makes voltage regulators out of Zener diodes. However, I suppose you could make a voltage regulator using a couple of LEDs although it probably wouldn't be as accurate.

For information on how to do this look at instructions for doing it with a Zener and then simply adapt them for using LEDs instead. For information on making a regulator using a Zener, type in ZENER VOLTAGE REGULATOR in Google. Here's a couple of examples:

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Reply to
mgkelson

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