45 Second Voice Recorder Module

45 second message recording without tapes or discs. Use it for phone messages, a voice memo pad, you name it!

When you need to record voice messages with the highest possible reliability, there’s no substitute for a solid-state voice recorder chip. There are no moving parts at all, so there are no tapes or belts to break, no heads to clog up with gunk, no motors to burn out and no bearings to jam. Instead, there’s just a memory chip to store and replay the message electronically, any number of times.

Because it’s solid-state, the message(s) can be played back instantly – there’s no tape to rewind. Small wonder that most telephone answering machines changed over to this kind of recording years ago.

We’ve described solid-state voice recorder projects in the past and they’ve been very popular. However, the special chips they used eventually became hard to get and so these projects eventually fell by the wayside.

This situation recently changed for the better again, when Jaycar Electronics managed to find a good source for a new voice recorder IC, the HK828. This made it possible for us to develop a new recorder design, incorporating not only the features that were popular in the earlier designs but a few more based on the requests we’ve received from readers over the years.

The new HK828 chip can store single or multiple messages with a total length of between 40 and 60 seconds, depending on the sampling rate and the voice quality you want. In our new recorder module, this chip is teamed up with a low-cost electret microphone to allow easy message recording, plus an LM386 power amplifier IC which allows the recorded messages to be played back through a small speaker.

In addition, we’ve made provision for the module to be hooked up to a 600Ω/600Ω line isolation transformer for coupling into another system; eg, an alarm system or a private phone line. There’s also a simple interface so that the module’s functions can be controlled via a PC or microcontroller.

The new recorder module runs from 6V DC and draws very little current, so it’s quite suitable for operating from either a battery (eg, four AA penlight cells) or from a regulated 6V plugpack supply.

By the way, since the HK828 voice recorder chip is only available from Jaycar Electronics in Australia and New Zealand, kits for the new recorder will only be available from Jaycar and its dealers

NOTE: ALL OF DATA OR METERIAL ON THIS BLOG IS JUST ONLY FOR STUDYING OR LEARNING PURPOSE ONLY,