Reducing the voltage

Thread Starter

zosh

Joined May 5, 2005
4
I have a 24v. 1500mah. battery that I need to run one LED that requiers 5v. 20hm.
and one phototransistor at 5v. 50mh. I would apriciate it if someone would help me figure out resister values to make this posible.

please be nice... im reely new!
 

David Bridgen

Joined Feb 10, 2005
278
Originally posted by zosh@May 6 2005, 12:20 AM
LED that requiers 5v. 20hm.
and one phototransistor at 5v. 50mh.
[post=7463]Quoted post[/post]​
Do you mean that the l.e.d. should be run at 20mA? What colour l.e.d. is it?

Please explain what you want to do with the phototransistor. What is the significance of 5V. What is 50mh?
 

Thread Starter

zosh

Joined May 5, 2005
4
Originally posted by David Bridgen@May 5 2005, 07:21 PM
Do you mean that the l.e.d. should be run at 20mA?  What colour l.e.d. is it?

Please explain what you want to do with the phototransistor.  What is the significance of 5V.  What is 50mh?
[post=7471]Quoted post[/post]​
sorry, im trying to make a circuit that i found on the internet that calls for the LED and Photosenser to detect when somthing pases between the two. I have found these components on the Jamco catalog. The operating values are hard to interpret and the best I can understand the operating values are as I stated earlier.

the LED is white.

I need a circuit drawing program to show it better.
 

David Bridgen

Joined Feb 10, 2005
278
Hi zosh,

Ok, can you tell me the catalogue part numbers and I will have look. And is that Jamco or maybe Jameco?

Oh, I use Micro$oft "Paint" to draw diagrams, and save them as gifs. Very easy.
 

David Bridgen

Joined Feb 10, 2005
278
1k2 = 1.2k.

The method of putting the multiplier where the point would go was introduced to reduce possible confusion in reading values from a poorly printed page.

0.12 ohms would be R12

1.2 ohms 1R2

12 ohms 12R

1.2M 1M2
 
Top