Hi, I'm building a LED dimming circuit and i have a question about the schematic,

http://www.reuk.co.uk/OtherImages/ne555-pwm-led-dimmer-circuit.gif

On the far left under R1 I don't understand what the IN4148 is. Well let me rephrase that, I know what it is a 50k pot connected with two diodes(Germanium in this case) but I do not understand what the IN4148 means. Could anyone care to explain? Any help would be nice.

Thanks

 

Its the part number of the diodes

With it u can find the datasheet like here

http://www.biltek.tubitak.gov.tr/gelisim/elektronik/dosyalar/7/1N4148.pdf

They are not germanium diodes.

 

Thank you,

I misread the page and it was talking about how ger. diodes can be put in place of the 1N4148 for more light out of the LED's.
Anyways thank you very much for answering my question in a short period of time. Howver one last question, what do you think of this LED dimming circuit?

Thanks
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You can replace the 1N4148 with schottky diodes since they have a lower forward voltage like the germanium diode but are much less sensitive to temperature.

hgmjr

 

I don't think the forward drop of the diodes will make any visible difference in the circuit operation. If if works from bright to dim, what's not to like? Low component count is always admirable.