Inside 1980s Sanyo Radio Alarm Clock

When my Dad was in college in Boston, there was a nearby RadioShack where he got all his parts.

I believe this is one of those purchase from said RadioShack. 

This alarm clock has been in my room (used by my brother) for as long as I can remember. I brought it to college with me as a desk clock. I thought it was a beautiful design, and I liked looking at it when I was working.

Cosmo Model CR 2001A

This past December I believe there was a power surge while we were on break. I came back to a broken hard drive and a busted alarm clock. I attempted to fix it. Here are some pictures of the insides for anyone interested!

There's a 9v battery in case of power outages to keep time.

A warning that I will not heed.

Taking off the front cover

I was stunned when I opened this up. It didn't hit me that in the 1980s, electronics were still very new.

The entire interior was very dusty and fragile.

A better look inside. The speaker is on the top, the clock circuit is on the left, and the AM/FM radio is on the right.

The circuit board for the switches and buttons is screwed to the top cover.

The circuit boards made back usually have phenolic as a substrate

Look at this crazy tuner! A string is wrapped around the potentiometer to move the pointer.

This is such a clever way of making a display.

The wires are kind of messy. Old circuit boards have a lot of smooth traces.

Top view of the radio board.

The clock doesn't display correctly.

I decided that perhaps the problem was in this IC chip.

This is the LM8560, which is used specifically for alarm clocks.

Thanks to eBay, I could buy one of these outdated chips!

I soldered in the new chip. It was painful, I broke several pads.

Notice anything broken? Me neither.

Broken pads are pretty hard to find, especially if you didn't make them. I had to jump some connections.

You also sometimes discover broken components! This capacitor was bulging like crazy and had a broken lead.

It's amazing how components deteriorate over time. There were plenty of resistors that didn't have paint on them anymore.

The college dorm life...

I couldn't fix the alarm clock. Unfortunately, the IC chip was not the issue. I tried tested out the other components.
However, every time I desoldered, tested, or even touched a component, I risked breaking a very delicate and irreplaceable part.

Primum non nocere - "First, do no harm" - from the Hippocratic Oath (??)

I decided that I was probably going to do more damage than help, so I put the clock back together.

At least the radio works!

Bird Alarm Clock

Who likes waking up to the sound of alarm bells?

From my experiences with different alarm clocks, I found that something that gradually gets louder wakes you up more patiently, comfortably, and fully than a sudden burst of obnoxious noise.

For example, for years I have used an alarm clock with the bells and hammer: every morning I would wake up still half asleep and extremely pissed.

I'm sure many people have this Ikea alarm clock...

Today, I use my cell phone to gradually play "Wake Up Everybody" louder. I usually wake up more invigorated and inspired... because of the song.

If you haven't caught on these are not my pictures... but this is my phone. I recommend it.

Usually when I do not wake up, my parents have to (thanks mom and dad).
So as a Holiday/ Anniversary gift, I decided to make an alarm clock, using my Ikea alarm clock and an old toy.



How I went about doing this is almost the same way I went about with my 555 mouse or my Phaser

Basically, you take some pre-built hardware and you use it's trigger for something else. I love this sort of work: it requires little programming, and its often cheaper and less time consuming because it involves cheap mass manufactured hardware that can be bought for pocket change, instead of expensive microcontrollers and raw parts.

I will proceed in talking about this project. Sorry, I did not take pictures.


1) open up the alarm clock. There should be a gearbox and three tabs on the PCB sticking out of the gearbox.
These three pads are Vcc (From battery pack, usually red wire is connected to it), GND (from battery pack, usually black wire), and some other pad with another color wire connected to it.

The third pad is connected to the motor of the alarm clock, if you trace it.
What happens is that when the alarm clock hits the time when it must activate, it grounds that third pad to connect the motor to ground and let electricity flow from cathode (-) to anode (+).

So, instead of grounding the motor, I would ground a robotic bird

2) open up whatever toy you want to activate when the alarm clock is grounded. Connect two wires to the battery pack: Vcc and GND.

Connect Vcc to whatever Vcc needs to be powered by, and the GND of the toy to the third pad on the alarm clock.

This is the basic concept of what's going on.
I had a voltage regulator in there to handle some Vcc issues... that was not the main circuit.
In essence, this circuit requires no components, just some rewiring.

okay where is the arduino stuff

For you arduino folks out there playing with multiplexing and H-Bridges, this might teach you an important concept.
Look at this instructables for example.

Also, read this for some understanding: Constants
You will further understand how microcontroller pins work.

Keso, the author of this instructables, connects the end of LEDs to other I/O pins.
He turns on one I/O pin and turns off the other I/O pin to turn on one LED. What he is actually doing when he turns of an I/O pin is grounding it, letting current flow.

Using this method, Keso was able to implement 6 LEDs when he only had 5 I/O pins.

Using this method, you could also make a low voltage motor turn both directions without an H-bridge. Simply connect one lead of each motor to an I/O pin, and write one pin 1, the other 0, and depending on whether the pins are 1,0 or 0,1, the motor will turn different directions.

I don't often see this method implemented, but to get the word out, it can do amazing things.

I hope that nugget of information helps.