How and Why I Changed It - Revision history

Gordonp: /* Pressure Switch Adjustments */

2025-05-04T22:46:57Z

Pressure Switch Adjustments

← Older revision		Revision as of 22:46, 4 May 2025
Line 18:		Line 18:
	== Pressure Switch Adjustments ==		== Pressure Switch Adjustments ==
	<ul><li>Use weakest spring (to get us into the lowest switching range, about 0.1" w.c. - 0.3" w.c.)<br>		<ul><li>Use weakest spring (to get us into the lowest switching range, about 0.1" w.c. - 0.3" w.c.)<br>
	<li>Turn out adjustment hex approx 3/4-turn from gently bottomed. This brings the switch-~~poing~~ down from the max. 0.3" w.c.<br>		<li>Turn out adjustment hex approx 3/4-turn from gently bottomed. This brings the switch-point down from the max. 0.3" w.c.<br>
	<li>Hysteresis of switch found to be about 0.075 water-column<br>		<li>Hysteresis of switch found to be about 0.075 water-column<br>
	</ul>		</ul>

2025-05-04T22:44:31Z

Pressure Switch Adjustments

← Older revision		Revision as of 22:44, 4 May 2025
Line 22:		Line 22:
	</ul>		</ul>
	<br>		<br>
	[[File:30s1_blower_pressure_rpm.png\|500px\|thumb\|~~left~~\|Blower-Pressure versus rpm, along with control-voltage]]<br>		[[File:30s1_blower_pressure_rpm.png\|500px\|thumb\|center\|Blower-Pressure versus rpm, along with control-voltage]]<br>
	<br>		<br>

	<br>		<br>

	== Operating Point ==		== Operating Point ==
	<ul><li>dial blower-speed to 2500rpm / 0.3" w.c.<br>		<ul><li>dial blower-speed to 2500rpm / 0.3" w.c.<br>

2025-05-04T22:43:33Z

Operating Point

← Older revision		Revision as of 22:43, 4 May 2025
Line 25:		Line 25:
	<br>		<br>

			<br>
	== Operating Point ==		== Operating Point ==
	<ul><li>dial blower-speed to 2500rpm / 0.3" w.c.<br>		<ul><li>dial blower-speed to 2500rpm / 0.3" w.c.<br>

2025-05-04T22:43:20Z

Pressure Switch Adjustments

← Older revision		Revision as of 22:43, 4 May 2025
Line 21:		Line 21:
	<li>Hysteresis of switch found to be about 0.075 water-column<br>		<li>Hysteresis of switch found to be about 0.075 water-column<br>
	</ul>		</ul>
			<br>

	[[File:30s1_blower_pressure_rpm.png\|500px\|thumb\|left\|Blower-Pressure versus rpm, along with control-voltage]]		[[File:30s1_blower_pressure_rpm.png\|500px\|thumb\|left\|Blower-Pressure versus rpm, along with control-voltage]]<br>
			<br>

	== Operating Point ==		== Operating Point ==

2025-05-04T22:42:56Z

Pressure Switch Adjustments

← Older revision		Revision as of 22:42, 4 May 2025
Line 22:		Line 22:
	</ul>		</ul>

	[[File:30s1_blower_pressure_rpm.png		[[File:30s1_blower_pressure_rpm.png\|500px\|thumb\|left\|Blower-Pressure versus rpm, along with control-voltage]]

	== Operating Point ==		== Operating Point ==

2025-05-04T22:41:56Z

Pressure Switch Adjustments

← Older revision		Revision as of 22:41, 4 May 2025
Line 22:		Line 22:
	</ul>		</ul>

	30s1_blower_pressure_rpm.png		[[File:30s1_blower_pressure_rpm.png

	== Operating Point ==		== Operating Point ==

2025-05-04T22:41:34Z

Pressure Switch Adjustments

← Older revision		Revision as of 22:41, 4 May 2025
Line 21:		Line 21:
	<li>Hysteresis of switch found to be about 0.075 water-column<br>		<li>Hysteresis of switch found to be about 0.075 water-column<br>
	</ul>		</ul>

			30s1_blower_pressure_rpm.png

	== Operating Point ==		== Operating Point ==

2025-05-04T22:36:31Z

Comment

← Older revision		Revision as of 22:36, 4 May 2025
Line 30:		Line 30:

	==Comment==		==Comment==
	Anecdotally, the adjustment procedure for the K102 thermal switch is to run the amp at just above full-rated-power, let it stabilize, then tweak R106 until it just shuts down. But following this means somewhat over 1kW DC input to the tube, and perhaps somewhere around 750W dissipation. At this dissipation level, with the stock blower's airflow, the anode temperature rises by xxxdegC.... far below damaging levels. I conclude that this sensor is not factory-set to save the tube, but rather to prevent the operator from exceeding the designed power-level. Saving the tube is a side-effect~~. I have re-prioritized, and made tube-safety paramount~~.		Anecdotally, the adjustment procedure for the K102 thermal switch is to run the amp at just above full-rated-power (1kW input), let it stabilize, then tweak R106 until it just shuts down. I conclude that this sensor is not factory-set to save the tube, but rather to prevent the operator from exceeding the designed power-level. Saving the tube is a side-effect.

2025-05-04T21:11:05Z

Pressure Switch Adjustments

← Older revision		Revision as of 21:11, 4 May 2025
Line 17:		Line 17:

	== Pressure Switch Adjustments ==		== Pressure Switch Adjustments ==
	<ul><li>Use weakest spring (to get us into the lowest range, about 0.1" w.c. - 0.3" w.c.)<br>		<ul><li>Use weakest spring (to get us into the lowest switching range, about 0.1" w.c. - 0.3" w.c.)<br>
	<li>Turn out adjustment hex approx 3/4-turn from gently bottomed<br>		<li>Turn out adjustment hex approx 3/4-turn from gently bottomed. This brings the switch-poing down from the max. 0.3" w.c.<br>
	<li>Hysteresis of switch found to be about 0.075 water-column<br>		<li>Hysteresis of switch found to be about 0.075 water-column<br>
	</ul>		</ul>

2025-05-04T21:10:16Z

Pressure Switch Adjustments

← Older revision		Revision as of 21:10, 4 May 2025
Line 17:		Line 17:

	== Pressure Switch Adjustments ==		== Pressure Switch Adjustments ==
	<ul><li>Use weakest spring<br>		<ul><li>Use weakest spring (to get us into the lowest range, about 0.1" w.c. - 0.3" w.c.)<br>
	<li>Turn out adjustment hex approx 3/4-turn from gently bottomed<br>		<li>Turn out adjustment hex approx 3/4-turn from gently bottomed<br>
	<li>Hysteresis of switch found to be about 0.075 water-column<br>		<li>Hysteresis of switch found to be about 0.075 water-column<br>