[Emc-users] Mesa 7I33 Aux Power
Hi all, I am getting a large voltage drop when I connect the analog outputs from the 7I33 to the load. With no load they show the correct voltages. The Mesa manual states Due to power supply limitations, The 7I33 has limited DC output drive capability and should not have loads of less than 5K Ohms on its analog outputs. The load is 10K, which seems to indicate that it should work. In fact I have had this hooked up to a supposedly identical system and it does work. My question is, if I add an Aux 5V supply (to 4 pin header P1) will that help with the DC output drive capacity of the Analogs? Thanks, Eric - Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mesa 7I33 Aux Power
On Wed, 2 Apr 2008, Eric H. Johnson wrote: Date: Wed, 2 Apr 2008 22:23:20 -0400 From: Eric H. Johnson [EMAIL PROTECTED] Reply-To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net To: 'Enhanced Machine Controller (EMC)' emc-users@lists.sourceforge.net Subject: [Emc-users] Mesa 7I33 Aux Power Hi all, I am getting a large voltage drop when I connect the analog outputs from the 7I33 to the load. With no load they show the correct voltages. The Mesa manual states Due to power supply limitations, The 7I33 has limited DC output drive capability and should not have loads of less than 5K Ohms on its analog outputs. The load is 10K, which seems to indicate that it should work. In fact I have had this hooked up to a supposedly identical system and it does work. My question is, if I add an Aux 5V supply (to 4 pin header P1) will that help with the DC output drive capacity of the Analogs? Thanks, Eric With all full scale outputs into 10K thats only 4 mA max from the +-OP amp supply. The +- OP amp power supply is capable of about 20 mA. Either its a bad 7I33, Your load is more than expected, or you do have a 5V power droop. I would check the 5V at the 7I33 card first. Peter Wallace - Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Mesa 7I33 Aux Power
Peter, I think that agrees with what I am seeing. I measured the load and in fact it is 20K ohm. I also tried an AUX 5 V supply, and as John said, it made almost no difference (went up by about 1/2 mA). The 5V looks to be good, there is other general I/O which all are working fine. I also connected a 9V battery directly to the load, and that does work. So it appears to be related to the current, although there is a big difference between 20 the mA available from the Mesa board and that available in a 9V battery. Thanks, Eric With all full scale outputs into 10K thats only 4 mA max from the +-OP amp supply. The +- OP amp power supply is capable of about 20 mA. Either its a bad 7I33, Your load is more than expected, or you do have a 5V power droop. I would check the 5V at the 7I33 card first. - Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
