Speaker To-Dirt wrote: > Hi All: > > Okay, so the question about what drives the current for the reactor > control winding. Here we go .... BOSS Service Manual p4-76 > > Looking at Figure 1040215, it can be seen that the emitters of the drive > transistors are returned to ground through resistors R1 and R2. A voltage > proportional to motor current is developed across these resistors and fed to > the ACC input at pins 9, 35, and 34. Looking at just the X-axis portion, see > that a portion of the apmplifiger Q5-Q4, where it is compared to the voltage > across the two forwrd-biased diodes D19 and D20. When it exceeds the diode > voltage Q5 will start to turn on and Q4 to turn off. This loweres the base > voltage of the PNP transistor Q3, turning it on and pulling up the base of > Q2. Q2 now turns on and pulls the base of Q22 down, turning it off and Q1 > with it. Q1 controls the DC through the control winding of the saturable > reactor; turning if off stops the control current and causes the pmpedance of > the power winding to increase greatly. > > I think this is where I'll start probing tomorrow. Thanks for pointing me in > this direction guys, it does look like it could cause my problem. But I'm > happy to see that the saturation control current is not under CPU control ... > that's good because I have not taken any steps to control it. And it also > means my memory is still somewhat sound. > OK, so it is an active current control scheme, I didn't know that. I think maybe some people rip out the ACC board when doing their conversion, obviously a mistake. When this circuit is working, it has to be better than a plain on-off control of the reactor.
Lucky you have the manual for this, it would be almost impossible to figure it out without that. Jon ------------------------------------------------------------------------------ The Palm PDK Hot Apps Program offers developers who use the Plug-In Development Kit to bring their C/C++ apps to Palm for a share of $1 Million in cash or HP Products. Visit us here for more details: http://p.sf.net/sfu/dev2dev-palm _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
