Schematic error, vol 3, ch 7, 9

Thread Starter

evandernoot

Joined Jan 8, 2008
1
It seems to me that the motor is connected to the anode gate of the SCS, instead of the anode as it should be in both drawings there (03320.png). It would probably be easier to simply put the motor between the two pushbutton paths shown.
 

Dcrunkilton

Joined Jul 31, 2004
422
After comparing the figure in question with the SCS diagram in the figure above this one, I agree that 03320.png is in error. I have changed the figure in the master copy at ibiblio. Though it may be a few days before I run the build script .
 

bit_eimer

Joined Sep 6, 2008
2
Hi,

I just registered today for the express purpose of bringing what I think is an error on vol 3, chap 7, page 9 to your attention. Having found this thread, I am not sure that the changes you to which you refer have been (correctly) made.

It still looks like there is a problem, namely:

The "DC Motor Start/Stop Circuit" and the "Equivalent Schematic with Two Transistors" do not topologically match. In the first the motor current comes through the Anode, whereas in the 2nd, the motor current comes through the Anode Gate.

In the "Review" notes we see "Typically, the load current through an SCS is carried by the anode gate ..." This leads me to believe that the "Equivalent Schematic" is correct, while the "DC Motor" circuit is in error.

I suppose its possible that the "schematic symbol" terminals are mislabeled, but it seems to be correct according to other sources on the web.
 

bit_eimer

Joined Sep 6, 2008
2
Note also that the text states the motor is turned off "by shorting the anode terminal to the cathode". This is in agreement with the "Equivalent Circuit" diagram, not with the "DC Motor" diagram (which shows the Anode Gate being shorted by the OFF switch).
 
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