A TTL timer project of yore

[Viktor] just pulled out another one of his decades-old projects. This time around it’s a timer he built using 7400 logic chips. It was a great way for him to learn about electronics, and ended up serving as his alarm clock every morning.

Two pieces of copper clad board were cut to the same size. One of them was etched to act as the circuit board. The other was outfitted as a face plate. The same type of transfer sheets used to mask the traces of the circuit were also used to apply labels to the face plate. It was then coated with acrylic spray to protect it and stave off corrosion. The clock keeps time based on a half-wave rectified signal. The source is from a transformer which steps mains voltage down to a safe level for the 7805 regulator that supplies the clock’s power bus.

We’re glad [Viktor] has been showing off these old projects. We’ve also enjoyed seeing a TV sleep timer he built. If you’ve got something neat for yester-year why not dust it off, post the details, and send us a tip about it?

Comments

  1. Ryoku says:

    I’m loving the fallout pitena of the built. age has done well for it in at least astetics. its like what you expect an eleivator face plate to be in close to 50-100 years. on the opposite side of the coin very interesting build with the psudo anolog led component. would be very FFVII by now if he used some vixe tubes =P

  2. Bill Gander says:

    This is a very cool old project. I love it! I would like to ask how/where you got labeling done for the controls back then. Was it in house? Thanks for the blast from the past :)

  3. GCooper says:

    I expect the lettering was done with the dry transfer approach. I haven’t seen it in years, but there used to be sheets of different sizes and fonts of letters and numbers which would be transferred to the surface with just a little pressure. Afterwards, a spray of clear krylon would protect the lettering.

  4. Tomasito says:

    Does someone knows where can I buy these type of switches online?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 96,459 other followers