zener reverse vltg - Electronic Circuits Projects Diagrams Free

bublee · 31st October 2009, 08:24 AM

can anybody tell me how to obtain a higher reverse blocking capacity from lower PIV zener ........

colin55 · 31st October 2009, 12:25 PM

Add zeners in series

bublee · 31st October 2009, 12:41 PM

thanx for the reply

Vizier87 · 31st October 2009, 04:44 PM

since we're on the topic of zeners... see this circuit:
http://www.electro-tech-online.com/a...rum-preamp.png

This circuit is proposed by audioguru for my disdrometer project
Acoustic Disdrometer

How does that zener clamp the output from a Piezo transducer?

audioguru · 31st October 2009, 05:42 PM

I was wrong.
The BAT85 is a Schottky diode, not a zener diode.
It conducts when the input goes negative by only 0.2V to avoid destruction of the input of the opamp that has a max allowed negative voltage of -0.3V.

Vizier87 · 1st November 2009, 02:20 PM

okay.... so a Schottky diode it is.. can it be replaced by the IN- series? Like the IN4148 or IN4001?

audioguru · 1st November 2009, 02:55 PM

The Schottky diode has the required 0.2V to 0.3V forward voltage to stop the negative input to the opamp from exceeding its max allowed negative voltage of -0.3V.

An ordinary diode has a forward voltage of 0.6V to 0.7V so the input of the opamp will be damaged.

yafch · 1st November 2009, 03:02 PM

1N400X series are general purpose diodes for AC-to-DC applictions. 1N4148 is a fast switching diode. schottky diodes are little bit different from these, because of their low forward voltage drop leading to lower levels of power loss compared to ordinary P-N junction diodes. schottky diodes are also known as surface barrier,hot carrier, or even hot electron diode. they are widely used in radio frequencies as mixer or detector,and in power applications as rectifiers where low forward voltage drop is required.

You can try google for different types of diodes or even wikipedia can help.

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31st October 2009, 08:24 AM	#1
bublee	zener reverse vltg can anybody tell me how to obtain a higher reverse blocking capacity from lower PIV zener ........

31st October 2009, 04:44 PM	#4
Vizier87	since we're on the topic of zeners... see this circuit: http://www.electro-tech-online.com/a...rum-preamp.png This circuit is proposed by audioguru for my disdrometer project Acoustic Disdrometer How does that zener clamp the output from a Piezo transducer? __________________ -The kinda guy who would improvise so much that you'd say "Here's 50 bucks for your Gigantron" http://vortexelectricaz.blogspot.com

31st October 2009, 05:42 PM	#5
audioguru	I was wrong. The BAT85 is a Schottky diode, not a zener diode. It conducts when the input goes negative by only 0.2V to avoid destruction of the input of the opamp that has a max allowed negative voltage of -0.3V. __________________ Uncle $crooge

1st November 2009, 02:20 PM	#6
Vizier87	okay.... so a Schottky diode it is.. can it be replaced by the IN- series? Like the IN4148 or IN4001? __________________ -The kinda guy who would improvise so much that you'd say "Here's 50 bucks for your Gigantron" http://vortexelectricaz.blogspot.com

1st November 2009, 02:55 PM	#7
audioguru	The Schottky diode has the required 0.2V to 0.3V forward voltage to stop the negative input to the opamp from exceeding its max allowed negative voltage of -0.3V. An ordinary diode has a forward voltage of 0.6V to 0.7V so the input of the opamp will be damaged. __________________ Uncle $crooge

1st November 2009, 03:02 PM	#8
yafch	1N400X series are general purpose diodes for AC-to-DC applictions. 1N4148 is a fast switching diode. schottky diodes are little bit different from these, because of their low forward voltage drop leading to lower levels of power loss compared to ordinary P-N junction diodes. schottky diodes are also known as surface barrier,hot carrier, or even hot electron diode. they are widely used in radio frequencies as mixer or detector,and in power applications as rectifiers where low forward voltage drop is required. You can try google for different types of diodes or even wikipedia can help.