12V Safety and Control - Revision history

Gordonp at 18:00, 12 August 2020

2020-08-12T18:00:07Z

← Older revision		Revision as of 18:00, 12 August 2020
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	[[Repair\|Back to Repair]]		[[Repair\|Back to Repair]]

			[[CR216 and BIAS Multi-Metering]]
	[[Primary AC Wiring]]

Gordonp at 17:48, 12 August 2020

2020-08-12T17:48:23Z

← Older revision		Revision as of 17:48, 12 August 2020
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	It is entirely possible that the light-bulb short I discovered was the cause of my T203 smoke-show.... I'll never know, for sure, because there seems to be several plausible causes :-O		It is entirely possible that the light-bulb short I discovered was the cause of my T203 smoke-show.... I'll never know, for sure, because there seems to be several plausible causes :-O

			[[Repair\|Back to Repair]]

			[[Primary AC Wiring]]

Gordonp at 17:46, 12 August 2020

2020-08-12T17:46:38Z

← Older revision		Revision as of 17:46, 12 August 2020
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	File:Improved_dial_lighting.jpg\|I re-soldered all light-connections, adding heatshrink sleeves over every terminal. I added large tubing over the entire socket for the two dial-bulbs. I sleeved the interconnecting wires to prevent wire-chafing. I added judicious bits of electrical-tape to prevent bracket-contact.		File:Improved_dial_lighting.jpg\|I re-soldered all light-connections, adding heatshrink sleeves over every terminal. I added large tubing over the entire socket for the two dial-bulbs. I sleeved the interconnecting wires to prevent wire-chafing. I added judicious bits of electrical-tape to prevent bracket-contact.
	</gallery>		</gallery>

			[[File:12v_safety_control_working.jpg\|500px\|thumb\|center]]

			SUCCESS!
			Everything 12V-related now works with the bench-supply. The Safety switches are all doing their thing (un-bypassing opens K203 nicely), the red "Amp Ready" light works, the front-panel "ON" and "OFF" push-buttons do their thing, the rear T/R works. Even the new lighting mod is nice: just the outer meter-lights turn on until the Safety interlock + timer is completed, then the dial-lamps turn on to let you know you're good-to-go!

			I was interested to see that the TOTAL 12V current-draw, with all lights and relays energized, is 0.75A. My new Peter Dahl transformer is rated 0.800A Continuous Commercial Service - a nice fit.

			It is entirely possible that the light-bulb short I discovered was the cause of my T203 smoke-show.... I'll never know, for sure, because there seems to be several plausible causes :-O

Gordonp at 17:38, 12 August 2020

2020-08-12T17:38:24Z

@@ Line 10: / Line 10: @@
 File:12v_control_test.jpg|Good! Injecting 12V onto CR206 anode allows K101 Antenna Change Over Relay to be controlled by the rear panel. Maximum current-draw is 0.31A with K101 and K205 engaged.
 File:12v_safety_interlock_test.jpg|More Good! Injecting 12V onto C211b let me try the "ON" button, and watch K203 engage! Maximum current-draw with K203 engaged was 0.21A.
 </gallery>

Gordonp: Created page with "My BIAS transformer was freshly replaced - in addition to the negative tube-bias voltage, this transformer also provides 12VAC for safety, and control. To ensure trouble-free..."

2020-08-12T17:30:45Z

Created page with "My BIAS transformer was freshly replaced - in addition to the negative tube-bias voltage, this transformer also provides 12VAC for safety, and control. To ensure trouble-free..."

New page

My BIAS transformer was freshly replaced - in addition to the negative tube-bias voltage, this transformer also provides 12VAC for safety, and control. To ensure trouble-free operation in this 12V safety and control, I did not initally hook up the BIAS transformer's 12VAC secondary, but rather I selectively applied a current-limited bench-supply.

My test strategy:
<ul>
<li>Use the bench-supply to inject 12V upwind of CR206, to verify wiring K203 through K101 Antenna Change-Over Relay, to the rear-panel T/R RCA-jack.</li>
<li>Inject 12V downwind of CR209, and selectively bypass S205 Lower Door Safety Switch, and the 3-min timer K202, and see if pressing S203 "ON" switch will engage relay K203</li>
<li>Inject 12V where the transformer will connect, bringing up all lights, allowing HV Relay to be enaged with front-panel "ON", and allowing the rear T/R jack to switch the antenna once the HV Relay has switched. The whole 12V enchilada :-)</li></ul>

<gallery widths="400px" heights="400px" perrow="2">
File:12v_control_test.jpg|Good! Injecting 12V onto CR206 anode allows K101 Antenna Change Over Relay to be controlled by the rear panel. Maximum current-draw is 0.31A with K101 and K205 engaged.
File:12v_safety_interlock_test.jpg|More Good! Injecting 12V onto C211b let me try the "ON" button, and watch K203 engage! Maximum current-draw with K203 engaged was 0.21A.
</gallery>