Categories

Glowing mercury thyratrons: Inside a 1940s Teletype switching power supply

Posted on Monday, September 24th, 2018 in power supply, Teardowns by DP

glowing-tubes

Ken Shirriff take a look inside a bulky DC power supply REC-30 rectifier, how it works and contrast it with a MacBook power supply:

We recently started restoring a Teletype Model 19, a Navy communication system introduced in the 1940s.14 This Teletype was powered by a bulky DC power supply called the “REC-30 rectifier”. The power supply uses special mercury-vapor thyratron tubes, which give off an eerie blue glow in operation, as you can see below.
The power supply is interesting, since it is an early switching power supply. (I realize it’s controversial to call this a switching power supply, but I don’t see a good reason to exclude it.) While switching power supplies are ubiquitous now (due to cheap high-voltage transistors), they were unusual in the 1940s. The REC-30 is very large—over 100 pounds—compared to about 10 ounces for a MacBook power supply, demonstrating the amazing improvements in power supplies since the 1940s. In this blog post, I take a look inside the power supply, discuss how it works, and contrast it with a MacBook power supply.

See the full post on Ken Shirriff ‘s blog.

This entry was posted on Monday, September 24th, 2018 at 10:50 pm and is filed under power supply, Teardowns. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

Leave a Reply

Notify me of followup comments via e-mail. You can also subscribe without commenting.

Recent Comments

  • Crawford: Pick me! Pick me!
  • Jack: May i have an SMD solder practice kit? Thanks!
  • Dan Ringer: PCB me!
  • Kurt: Whose woods these are I think I know. His house is in the village though; He will not mind me stopping here To watch his...
  • Sjaak: I love those spade connectors. Where to get them?