Star Tech Journal
Issue: 1987-July - Vol 9 Issue 5 - Page 5
July 1987 (5)
STAR*TECH Journal
The reference voltage is easy, a zener
diode would be sufficient, but the rest of
the "goodies" would require quite a bit of
work. Fortunately the masters of silicon
magic have smiled upon us. Figure 3 shows
the pinout and partial inner structure of
the TL-494C PWM switching regulator chip.
It contains all of the functions we need.
It even has a couple of extras. Pin 13 is
the outµit control pin. If for any reason
this pin goes "low" it shuts off the
chips' outµits. Very useful for things
like over-voltage and over-current
protection.
Premier SPRING BREAK Plastic
Ramp Breakage
By Premier customer Service
Bensenville, Illinois
PROBLEM: Breakage of the plastic ramp on
the left side.
SOLUTION: Addition of 21158 Ball Deflector
to the left side of the ramp -samples
only- (see drawing for the proper
placement).
* Ball Deflectors are available at Premier
Technology at no charge.
It also has a pin called "Dead Time
Control." This is used to set the mininum
time between when one of the switching
transistors is supposed to turn off and
the other is to tum on. In other words,
it is used to ensure that if one of the
transistors has a slow recovery time it is
~ not still conducting when the other starts
,\ • to conduct.
I believe that should do it for now. Next
nonth we take our TL-494C and connect it
to our supply, and then discuss some
troubleshooting.
MANUFACTURER'S NUMBERS
Customer Service
Arachnid 800/435-8319
Ardac 800/321-07B5
Atari/Namco 408/434-3950
Bally/Midway/Senta 312/451-9200
Capcom 408/745-7081
Cinematronics 619/562-7000
Data East 408/286-7074
Doyle 208/743-3B11
Exidy 800/538-8402
Konami 312/595-1443
Memetron 312/629-6500
Merit 800/445-9353
Nichibutsu 213/408-0518
Nintendo 800/633-3236
Premier 312/350-0400
Romstar 213/539-2744
Sage 408/435-0201
Showcase 800/642-7263
Taito 312/520-9280
Tecmo 800/457-6050
Tradewest 214/874-2683
Univid 800/321-2778
Wico 800/323-4258
Williams 312/267-2240
11
BALL DEFLECTOR
PART NO. 21158
1-~
½-i , -- ' I
'\-.8 ..,
..._..,
..,..,_
1. Using Ball Deflector, part# 21158 as a
tenplate, press firmly against plastic
ramp and position so that it is about
3/16" ahead of the front edge of the
plastic ramp and not touching the
mini-post rubber ring. At this time scribe
the two nounting holes on the playboard,
see figure 1.
2. Center µinch the two scribed nollllting
holes and drill through the playboard
using .093 (3/32") drill. Mount the Ball
Deflector with the two screws provided.
3. Installation is now complete.
Murphy's Law #905
Science is true. Don't be misled by facts.
STAR*TECH Journal
The reference voltage is easy, a zener
diode would be sufficient, but the rest of
the "goodies" would require quite a bit of
work. Fortunately the masters of silicon
magic have smiled upon us. Figure 3 shows
the pinout and partial inner structure of
the TL-494C PWM switching regulator chip.
It contains all of the functions we need.
It even has a couple of extras. Pin 13 is
the outµit control pin. If for any reason
this pin goes "low" it shuts off the
chips' outµits. Very useful for things
like over-voltage and over-current
protection.
Premier SPRING BREAK Plastic
Ramp Breakage
By Premier customer Service
Bensenville, Illinois
PROBLEM: Breakage of the plastic ramp on
the left side.
SOLUTION: Addition of 21158 Ball Deflector
to the left side of the ramp -samples
only- (see drawing for the proper
placement).
* Ball Deflectors are available at Premier
Technology at no charge.
It also has a pin called "Dead Time
Control." This is used to set the mininum
time between when one of the switching
transistors is supposed to turn off and
the other is to tum on. In other words,
it is used to ensure that if one of the
transistors has a slow recovery time it is
~ not still conducting when the other starts
,\ • to conduct.
I believe that should do it for now. Next
nonth we take our TL-494C and connect it
to our supply, and then discuss some
troubleshooting.
MANUFACTURER'S NUMBERS
Customer Service
Arachnid 800/435-8319
Ardac 800/321-07B5
Atari/Namco 408/434-3950
Bally/Midway/Senta 312/451-9200
Capcom 408/745-7081
Cinematronics 619/562-7000
Data East 408/286-7074
Doyle 208/743-3B11
Exidy 800/538-8402
Konami 312/595-1443
Memetron 312/629-6500
Merit 800/445-9353
Nichibutsu 213/408-0518
Nintendo 800/633-3236
Premier 312/350-0400
Romstar 213/539-2744
Sage 408/435-0201
Showcase 800/642-7263
Taito 312/520-9280
Tecmo 800/457-6050
Tradewest 214/874-2683
Univid 800/321-2778
Wico 800/323-4258
Williams 312/267-2240
11
BALL DEFLECTOR
PART NO. 21158
1-~
½-i , -- ' I
'\-.8 ..,
..._..,
..,..,_
1. Using Ball Deflector, part# 21158 as a
tenplate, press firmly against plastic
ramp and position so that it is about
3/16" ahead of the front edge of the
plastic ramp and not touching the
mini-post rubber ring. At this time scribe
the two nounting holes on the playboard,
see figure 1.
2. Center µinch the two scribed nollllting
holes and drill through the playboard
using .093 (3/32") drill. Mount the Ball
Deflector with the two screws provided.
3. Installation is now complete.
Murphy's Law #905
Science is true. Don't be misled by facts.
Future scanning projects are planned by the International Arcade Museum Library (IAML).