need advice on digital circuit as im stumped?

[digitalme1]

hi there, im new to the forum so hi there, ive been building this digital circuit from plans off the internet to electronic control the lead screw of a lathe..all was going well until this circuit plan for pulse division(used to give ratios of spindle speed)..please look at the circuit diagram and read the text of circuit function and tell me if is possible, i dont understand how it can work the way the designer says it does..im a novice to digital electronics so im learning all the time..please point me in the right direction as im stumped, how can you preset this circuit(40193) to zero when counting up or preset it to the preset value when counting down, any help would be greatly appreciated.

designers description

Lead Screw ( = Multiplier) and Main Spindle ( = Divider) Counter (Drawing 6):

Both counters are identical. Since the system is bidirectional, these counters have to be able to reverse their counting direction at any time while counting, without losing a pulse. When counting up, they are initially set to zero and are compared to the preset value. When the preset value is reached, they are set to zero again. When counting down, they are set to the preset value and compared to zero. Upon reaching zero, they are set to the preset value again.
Each time the multiplier or divider counter is set to zero or to the preset value, it passes on a counting pulse to the phase counter. To avoid the phase counter to receive an up count and a down count simultaneously, which would result in an undetermined condition with possible loss of a pulse, pulses from the divider counter (main spindle) to the phase counter are clocked with C4 and from the multiplier counter (lead screw) with C6.

**broken link removed**

 

[digitalme1]

i havnt been very clear in my description, i know the function of the 40193 up/down counter..when you apply a preset value to the p0-3 inputs the 40193 counts up or down and when q0-3 eqauls the preset a pulse is passed on, when this happens the preset value is loaded using the load (preset signal)..what i cant see is how from the designers description you can preset the 40193 with a fixed value say(0110=6..every 6th pulse is passed on, thus performing a pulse division)but also passing on a pulse when the q0-3 is at zero (0000)..i hope this is clearer.

 

[ericgibbs]

i havnt been very clear in my description, i know the function of the 40193 up/down counter..when you apply a preset value to the p0-3 inputs the 40193 counts up or down and when q0-3 eqauls the preset a pulse is passed on, when this happens the preset value is loaded using the load (preset signal)..what i cant see is how from the designers description you can preset the 40193 with a fixed value say(0110=6..every 6th pulse is passed on, thus performing a pulse division)but also passing on a pulse when the q0-3 is at zero (0000)..i hope this is clearer.

Hi,
A quick look at the diagram shows errors.
Look at the RED and BLUE enable lines to the Parallel load gating.??

They seem to be floating.??

EDIT:
hi,
If you parallel load the 193 with '6' then you would count down until the 'terminal count is detected.

Counting up, you would test the outputs of the 193 for the binary '6' state, using the gates on the outputs of the 193, having either cleared the 193 or parallel loaded with '0' , before counting