CS>FW: CS>Current Limiting diodes

[Dan Nave]

Title: FW: CS>Current Limiting diodes

Correction: That should read (ie. 0.9 ma or 1.1 ma)... I think "current limiting diodes" is something of a misnomer, kind of like products marked "unscented" which have scent in it, or like "Liberal" and "Conservative" in the political realm... By the way, don't buy the exact 1.0 ma diode, buy one tenth ma less than or greater than (ie. 0.9 ma or 2.1 ma).  They are less than half the price of the exact 1/0 ma diodes. Dan IV.5 - Current Limiting diodes? Constant current two-terminal devices can be made by shorting the gate and the source of a JFET together. When the FET is forward biased, this results in a nearly constant current for voltages ranging from roughly 2V up to 300V (or the breakdown voltage of the device in question). In reverse bias, this kind of constant current device conducts as a junction diode (so one can oppose two such devices in series to regulate AC current). Siliconix makes two-lead FET current-limiting diodes ranging from 0.24 mA (J500) through 4.7 mA (J511) in plastic packages, and from 1.6 mA (CR160) through 4.7 mA (CR470) in metal TO-18 packages. National Semiconductor makes a three-terminal adjustable device, the LM134/LM234/LM334, that acts as a resistor-programmed current source diode, analogous to the 'programmable Zener' TL431. Adjustment range is 1.0 uA to 10 mA, and voltage compliance is from 1V to 40V (or 30V for some versions). The current is slightly temperature-dependent (this may be useful, or can be eliminated with a diode added to the adjustment resistor). -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.408 / Virus Database: 268.13.4/476 - Release Date: 10/14/2006 -- The Silver List is a moderated forum for discussing Colloidal Silver. Instructions for unsubscribing are posted at: http://silverlist.org To post, address your message to: silver-list@eskimo.com Address Off-Topic messages to: silver-off-topic-l...@eskimo.com The Silver List and Off Topic List archives are currently down... List maintainer: Mike Devour <mdev...@eskimo.com>

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Version: 7.1.408 / Virus Database: 268.13.4/476 - Release Date: 10/14/2006