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HELP Astron 70 amp PS
HELP Astron 70 amp PS
I have a astron 70 amp power supply and was hooking up a transmitter to it and I pulled the power supply closer to me and the positive wire came loose and hit the ground terminal on power supply. Now when I turn it on you can hear the power supply turn on and the light on the power swithch comes on, but no volts comes up on the meter. I checked the terminals on the back and no volt, very little if at all. The outside fuse is good. I took off top cover and I don't see and internal fuse. Is there a diode I should be looking for? I'm sure it has to have some kind of protection if the wires are reversed. Any help would be great. Rich |
wrote in message ... HELP Astron 70 amp PS I have a astron 70 amp power supply and was hooking up a transmitter to it and I pulled the power supply closer to me and the positive wire came loose and hit the ground terminal on power supply. Now when I turn it on you can hear the power supply turn on and the light on the power swithch comes on, but no volts comes up on the meter. I checked the terminals on the back and no volt, very little if Check to see if any or all of the pass transistors are shorted. If so the crowbar may be kicking in and keeping the output voltage low. Doubt this is the case as the fuse would probably blow. Otherwise check the 723 voltage regulator IC and see if it is putting out any voltage. YOu may just have to change it out as that seems to be a weak point of the supplies. |
wrote in message ... HELP Astron 70 amp PS I have a astron 70 amp power supply and was hooking up a transmitter to it and I pulled the power supply closer to me and the positive wire came loose and hit the ground terminal on power supply. Now when I turn it on you can hear the power supply turn on and the light on the power swithch comes on, but no volts comes up on the meter. I checked the terminals on the back and no volt, very little if Check to see if any or all of the pass transistors are shorted. If so the crowbar may be kicking in and keeping the output voltage low. Doubt this is the case as the fuse would probably blow. Otherwise check the 723 voltage regulator IC and see if it is putting out any voltage. YOu may just have to change it out as that seems to be a weak point of the supplies. |
wrote in message ... HELP Astron 70 amp PS I have a astron 70 amp power supply and was hooking up a transmitter to it and I pulled the power supply closer to me and the positive wire came loose and hit the ground terminal on power supply. Now when I turn it on you can hear the power supply turn on and the light on the power swithch comes on, but no volts comes up on the meter. I checked the terminals on the back and no volt, very little if Check to see if any or all of the pass transistors are shorted. If so the crowbar may be kicking in and keeping the output voltage low. Doubt this is the case as the fuse would probably blow. Otherwise check the 723 voltage regulator IC and see if it is putting out any voltage. YOu may just have to change it out as that seems to be a weak point of the supplies. |
In article . net,
"Ralph Mowery" wrote: Check to see if any or all of the pass transistors are shorted. Bzzzt, wrong, would you like to try for what is behind Door #3? If the Pass Transistors were shorted, you would see the voltage of the filter capacitors and rectifiers on the output. He stated that he had "No or little output voltage". This would indicate that the Pass Transistors are OPEN, blown that way by the High Current when the output was shorted, or the rectifiers are blown OPEN and not producing any DC to the filter caps. Me |
In article . net,
"Ralph Mowery" wrote: Check to see if any or all of the pass transistors are shorted. Bzzzt, wrong, would you like to try for what is behind Door #3? If the Pass Transistors were shorted, you would see the voltage of the filter capacitors and rectifiers on the output. He stated that he had "No or little output voltage". This would indicate that the Pass Transistors are OPEN, blown that way by the High Current when the output was shorted, or the rectifiers are blown OPEN and not producing any DC to the filter caps. Me |
In article . net,
"Ralph Mowery" wrote: Check to see if any or all of the pass transistors are shorted. Bzzzt, wrong, would you like to try for what is behind Door #3? If the Pass Transistors were shorted, you would see the voltage of the filter capacitors and rectifiers on the output. He stated that he had "No or little output voltage". This would indicate that the Pass Transistors are OPEN, blown that way by the High Current when the output was shorted, or the rectifiers are blown OPEN and not producing any DC to the filter caps. Me |
In article ,
Me wrote: Check to see if any or all of the pass transistors are shorted. Bzzzt, wrong, would you like to try for what is behind Door #3? If the Pass Transistors were shorted, you would see the voltage of the filter capacitors and rectifiers on the output. He stated that he had "No or little output voltage". This would indicate that the Pass Transistors are OPEN, blown that way by the High Current when the output was shorted, or the rectifiers are blown OPEN and not producing any DC to the filter caps. It's still darned good advice. If there's a fuse or fusible component between the DC filter caps and the pass transistor, it might very well have blown if the pass transistor shorted during an overload. From what I've heard, bipolar power transistors are as likely to fail shorted as they are to fail open. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
In article ,
Me wrote: Check to see if any or all of the pass transistors are shorted. Bzzzt, wrong, would you like to try for what is behind Door #3? If the Pass Transistors were shorted, you would see the voltage of the filter capacitors and rectifiers on the output. He stated that he had "No or little output voltage". This would indicate that the Pass Transistors are OPEN, blown that way by the High Current when the output was shorted, or the rectifiers are blown OPEN and not producing any DC to the filter caps. It's still darned good advice. If there's a fuse or fusible component between the DC filter caps and the pass transistor, it might very well have blown if the pass transistor shorted during an overload. From what I've heard, bipolar power transistors are as likely to fail shorted as they are to fail open. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
In article ,
Me wrote: Check to see if any or all of the pass transistors are shorted. Bzzzt, wrong, would you like to try for what is behind Door #3? If the Pass Transistors were shorted, you would see the voltage of the filter capacitors and rectifiers on the output. He stated that he had "No or little output voltage". This would indicate that the Pass Transistors are OPEN, blown that way by the High Current when the output was shorted, or the rectifiers are blown OPEN and not producing any DC to the filter caps. It's still darned good advice. If there's a fuse or fusible component between the DC filter caps and the pass transistor, it might very well have blown if the pass transistor shorted during an overload. From what I've heard, bipolar power transistors are as likely to fail shorted as they are to fail open. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
Check to see if any or all of the pass transistors are shorted. Bzzzt, wrong, would you like to try for what is behind Door #3? If the Pass Transistors were shorted, you would see the voltage of the filter capacitors and rectifiers on the output. He stated that he had "No or little output voltage". This would indicate that the Pass Transistors are OPEN, blown that way by the High Current when the output was shorted, or the rectifiers are blown OPEN and not producing any DC to the filter caps. I don't debate or try very hard to teach idiots but the Astrons have a crowbar circuit that will activate and the output voltage will drop to a very low value. Most simiconductors fail by shorting and are not blown open. |
Check to see if any or all of the pass transistors are shorted. Bzzzt, wrong, would you like to try for what is behind Door #3? If the Pass Transistors were shorted, you would see the voltage of the filter capacitors and rectifiers on the output. He stated that he had "No or little output voltage". This would indicate that the Pass Transistors are OPEN, blown that way by the High Current when the output was shorted, or the rectifiers are blown OPEN and not producing any DC to the filter caps. I don't debate or try very hard to teach idiots but the Astrons have a crowbar circuit that will activate and the output voltage will drop to a very low value. Most simiconductors fail by shorting and are not blown open. |
Check to see if any or all of the pass transistors are shorted. Bzzzt, wrong, would you like to try for what is behind Door #3? If the Pass Transistors were shorted, you would see the voltage of the filter capacitors and rectifiers on the output. He stated that he had "No or little output voltage". This would indicate that the Pass Transistors are OPEN, blown that way by the High Current when the output was shorted, or the rectifiers are blown OPEN and not producing any DC to the filter caps. I don't debate or try very hard to teach idiots but the Astrons have a crowbar circuit that will activate and the output voltage will drop to a very low value. Most simiconductors fail by shorting and are not blown open. |
In article . net,
"Ralph Mowery" wrote: I don't debate or try very hard to teach idiots but the Astrons have a crowbar circuit that will activate and the output voltage will drop to a very low value. Most simiconductors fail by shorting and are not blown open. Bzzzt, Wrong again, If the Crowbar SCR is shorted or in the conducting state, then the whole output of the powersupply would be dissipated by it, and that would then cause the Pass transistors to fail from overcurrent, or the input AC fuse to fail from overcurrent. He stated in the original post, that the AC fuse was GOOD, but he was getting no output voltage on the DC terminals, therefore there would be an OPEN somewhere in the supply that was caused by the OVER CURRENT of touching the DC Terminals together. Your analysis skills are a bit lacking here dude. Me |
In article . net,
"Ralph Mowery" wrote: I don't debate or try very hard to teach idiots but the Astrons have a crowbar circuit that will activate and the output voltage will drop to a very low value. Most simiconductors fail by shorting and are not blown open. Bzzzt, Wrong again, If the Crowbar SCR is shorted or in the conducting state, then the whole output of the powersupply would be dissipated by it, and that would then cause the Pass transistors to fail from overcurrent, or the input AC fuse to fail from overcurrent. He stated in the original post, that the AC fuse was GOOD, but he was getting no output voltage on the DC terminals, therefore there would be an OPEN somewhere in the supply that was caused by the OVER CURRENT of touching the DC Terminals together. Your analysis skills are a bit lacking here dude. Me |
In article . net,
"Ralph Mowery" wrote: I don't debate or try very hard to teach idiots but the Astrons have a crowbar circuit that will activate and the output voltage will drop to a very low value. Most simiconductors fail by shorting and are not blown open. Bzzzt, Wrong again, If the Crowbar SCR is shorted or in the conducting state, then the whole output of the powersupply would be dissipated by it, and that would then cause the Pass transistors to fail from overcurrent, or the input AC fuse to fail from overcurrent. He stated in the original post, that the AC fuse was GOOD, but he was getting no output voltage on the DC terminals, therefore there would be an OPEN somewhere in the supply that was caused by the OVER CURRENT of touching the DC Terminals together. Your analysis skills are a bit lacking here dude. Me |
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