Motor controls.... DODE.

Status
Not open for further replies.

xformer

Senior Member
Location
Dallas, Tx
Occupation
Master Electrician
Hello all,

Anyone have a schematic for an old DODE relay? I am wondering how these things functioned before the advent of micro circuitry.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Hello all,

Anyone have a schematic for an old DODE relay? I am wondering how these things functioned before the advent of micro circuitry.
I assume you mean Delay Off after De-energization.

Some used capacitors, others used oil in dashpots, but many used pneumatics.
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
We used to use some that we called DODO relays, Delay On, Delay Off. They were made by Mallory (I think it was), and used heaters. When you energized them, the heater warmed up and a bi-metal strip bent, changing the contact state. After you powered off, the heater turned off, the bi-metal strip cooled off and returned to its normal state. I still have a couple in a box somewhere I think. They were in glass vacuum tubes, you could tell when they were on because the heater coils glowed orange.
 
Status
Not open for further replies.
Top