Arthur Alchin
17-04-2011, 05:42 AM
Wanted to make a dew heater controller for my home made dew heaters (nichrome wire).
The main heater for the nose of my meade lxd75 8" SN (made of nichrome wire) drawers just over 1 amp at 12.5 volts delivering about 13-14 watts which is ample for the dew beating purpose but i needed a better controller than just a 1 to 5 ohm variable pot.
Found a website called "kitstop.com.au" who sell a Pulse width Modulator that is rated 40 watts (they also have larger capacity ones). It is about $11 something for the kit or $18 something preassembled ( + postage of about $6) all you need to get is a box to put it in, a couple of appropriate plugs/sockets and a knob.
At this size it doesn't require a heatsink.
I am impressed as (from memory) it runs at 100hz with a varying pulse width of 5-100%.
I am interested in feedback from others members.
PS: mine is working extremely well.
The main heater for the nose of my meade lxd75 8" SN (made of nichrome wire) drawers just over 1 amp at 12.5 volts delivering about 13-14 watts which is ample for the dew beating purpose but i needed a better controller than just a 1 to 5 ohm variable pot.
Found a website called "kitstop.com.au" who sell a Pulse width Modulator that is rated 40 watts (they also have larger capacity ones). It is about $11 something for the kit or $18 something preassembled ( + postage of about $6) all you need to get is a box to put it in, a couple of appropriate plugs/sockets and a knob.
At this size it doesn't require a heatsink.
I am impressed as (from memory) it runs at 100hz with a varying pulse width of 5-100%.
I am interested in feedback from others members.
PS: mine is working extremely well.