On Thursday 23 July 2015 09:34:06 Todd Zuercher wrote: > I am trying to replace a control that died and had to change the drive > too. I picked up an AMC DR100EE30A40NAC cheep on ebay. link to the > spec sheet for the drive > http://www.a-m-c.com/download/datasheet/dr100ee30a40nac.pdf
This controller expects the usual A/B/Z quadrature signals, in differential mode. This means that for single ended usage, the - terminal of each input can be grounded signal wise, but it should be biased at nominally 2 to 2.5 volts so then the other, active signal coming in on the + line goes both above, and below this bias point as it swings. > Like most drives this is set up for 5v encoder (either single or > double ended). The problem is that the encoder from the old system was > set up using a 10v single ended signal. The old encoder is an Eltra > EH63GB500S8/24P10X3PR8 link to the encoder specs > http://rankinusa.com/products/files/932e6_15.%20EH-EF%2080%20C-P-K.pdf Link is dead from here. You are running on 5 volts, so I would use a 270 ohm and the 330 ohm resistor in series from 5 volts to ground, with the 270 on the ground end, and tie the - input to the junction of the two resistors, giving a bias of about 2.25 volts to each of the - terminals. > What would be the best way to use this encoder with this drive? > > I tried to ask this question while the mail list was down. So I also > asked on the forum PCW answered there with the suggestion of using a > couple of 330ohm resisters to make a voltage divider. This should also work, giving a bias of 2.5 volts. Depending on the circuitry that could be high for TTL stuff, depending on how high the + side rises when its in the high state. Looking at it with a DC coupled scope, I would choose a bias voltage which is midway between the input swings high & low. Best noise immunity that way. > I'll probably do > what PCW suggested. Does anyone else have any differing opinions? How > does one calculate what would be the right size resisters to use in > something like this? As long as the wattage rating is bigger than the power disipated, it won't care. Anything over a quarter watt should be fine. My calculator says thats 42 milliwatts worth of heat. Thats a shrug, Todd. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
