Looking to drop 6 volts dc to 4.5 volts dc

.D.E · 2006-09-28T18:41:29+00:00

I'm looking to add a mod to my pinball machine with a couple of led's and need to drop 6 volts dc down to 4.5 volts dc. Can anyone suggest which resistor to use?Thanks.-- _____________________________Later.Have a better one.D.E.To email me back, remove ""

Sep 28, 2006 24 Replies

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ehsjr 19 years ago

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.

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Al 19 years ago

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!

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Daniel 19 years ago

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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mgkelson 19 years ago

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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