AAØZZ EZKeyer III 23 November 2014
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Copyright 2014 AAØZZ
Figure 6.2 – Cover Installed
That’s it! The EZKeyer is ready to use.
7 Using the EZKeyer III
7.1 Powering the EZKeyer III
Powering the keyer is left to the builder. The voltage range must be within 3 to 5.5 V DC. Note that the
speaker volume is reduced when running at lower voltages. Three AA batteries make nice battery pack
for the keyer and the batteries should last for a year or more.
There is plenty of room in the case for the 3-cell AA battery pack.
Make sure you measure the voltage before connecting the batteries to the board!
7.2 Installing a larger speaker
If you decide you want more volume coming from the keyer than the on-board speaker can provide, you
can use an external speaker. One common, inexpensive speaker that has been tested with good
results is Radio Shack part number 273-073. For maximum volume, the case has specifically been
designed to accommodate piezo part number 102-2200-ND from Digikey. (This piezo is shown in
Figure 7.1.)
If you chose to use an external speaker, remove the on-board speaker first and attach the wires for the
external speaker to these holes in the board. Be sure to observe polarity. The speakers can be
attached on its edge facing the operator and lining up with the hole grid on the case. This will give a
noticeable increase in speaker volume. Other speakers can be used as well. To keep the speaker
from moving around you can hold it in place with a piece of folded-up tape wedged between the
speaker and the PCB or you can use a piece of foam or other material. If you use the large Digikey
piezo (102-2200-ND), make sure you mount it with the larger hole facing forward (toward the enclosure
grid).