Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

zener diode usage in a reference schematic circuit

Status
Not open for further replies.

robismyname

Full Member level 6
Joined
Jan 17, 2008
Messages
390
Helped
11
Reputation
22
Reaction score
9
Trophy points
1,298
Location
Central Florida
Activity points
4,603
I have a circuit that is used for manipulating solenoids. Basically I need help understanding the portion of the circuit C11,D8 and R19.

I also need help understanding C10, R14 and D7.

Why is D7 being used in reverse bias? Does a zener diode that operates in forward bias have the same i-v characteristics of a regular diode?

91_1315453847.png
 

Raza

Advanced Member level 3
Joined
Feb 10, 2002
Messages
829
Helped
265
Reputation
528
Reaction score
258
Trophy points
1,343
Location
PAK
Activity points
4,486
Hi,
These diodes you referred are not Zener Diodes. These are New Generation Power Diodes (Super Barrier Rectifier). They have an edge on Shottky Diodes in low voltage usage.
Here your referred circuits working as snubber network. If you see the Solenoids are fed positive supply voltage directly and the controlling FETS are making ground circuit, so for bypassing any transient due to inductive load this circuit is used.
If you want information on SBRs here is the link for a better understanding.

https://digitalcommons.calpoly.edu/...c&sei-redir=1#search="supr barrier rectifier"

Hope it helps.
 

FvM

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
48,381
Helped
14,245
Reputation
28,751
Reaction score
12,932
Trophy points
1,393
Location
Bochum, Germany
Activity points
280,020
To understand the basic circuit function, you can consider the parts simply as regular diodes. For a detail analysis, you would need to know the coil R and L numbers. In a short, the circuit is intended to absorb inductive overvoltages. A simple freewheeling diode is apparently not suffcient, most likely releasing the coil too slow.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top