Thanks for this video! I'm an elderly {74} Canadian man who is more-or-less retired from designing & manufacturing {in my tiny home basement office & workshop} specialty electronic equipment for the geophysics community. I was entirely unaware of the Ericsson selector until this video. A very clever design, and quite possibly superior to {more compact than} the earlier Strowger step-by-step mechanism widely used in North America beginning in the late 1890s. The lesson we learn is that there are inventive people all over the world. God bless all of them - we stand on the shoulders of giants, to quote Sir Isaac Newton.

Thank you for this video, I was originally a Strowger BT Technical Officer in South Yorkshire UK. left BT as an Ericsson AXE10 engineer and became a consultant (1998) at Ericsson Stockholm Network Operations Centre. I came across the bank system as part of demonstration at the Museum of Engineering in Stockholm whilst working and living there. Fascinating how both Strowger and this system had group and final selectors but used differing mechanisms as you have indicated the design of these systems was admirable. 🙂

Well done! A clear explanation of how the Ericsson pancake switch works. Using the Arduino with relay drivers is a great way to do the demo. Thanks for doing this.

I like the description. Amazing it was originally built without electronics. I recently did a project that rings another rotary phone; the Arduino counts the dial pulses, switches 12 volts from powering the line to powering the ring generator, and sets the correct line selector relay to ring the other phone. Between rings, the Arduino checks for off hook voltage, if so stops the ringing.

Beautiful ! Knap werk en mooie demo van deze pannekoek 👍

I remember as a young engineer working with AGF in Stavanger Telephone Exchange. I saw it later in a technical museum in Stockholm.

Thanks for a really good description and demo of the 500 selector.

The best thing was this system worked even if you had a local black out, you could use your phone.

Amazing, thanks for the demo, its a work of art :)

Nice! It’s clear you invested a great amount of care to demonstrate this amazing component. It makes me wonder if the Stroger step by step was prior or subsequent.

Love this! Hope more people see it :-)

@8:40 - This is why it used to be possible to dial an old telephone without using the dial (like when some overzealous soul put a padlock on the dial wheel). You just tapped the hook as many times as the number (tap three times, pause, tap seven times, pause, tap once then wait for the call to connect).

That's fascinating, thank you. I've never heard of those devices before. Very nice demo.

How did the system work before the invention of an Arduino? How was the number dialled remembered before being sent to the selector?

Does each user have their own selector?

I see that it can only use one phone at a time, how was this deployed to allow for more then one phone call at once? If we had the maximum 500 phones you would have 500 switches and each phone would need to be connected via 500 wires in a horrific mess of cables, which I don't think is practical

Hi, thank you for this video, I have an old GSM 900 car cell phone (1993). In my country, 2G is no longer available, so the phone does not work anymore. I tried to find out if it would be possible to convert this phone to 4G, unfortunately I couldn't find anyone who could help me. What do you think, is such a conversion possible?