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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

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Old 16th Dec 2010, 6:21 pm   #1
batterymax
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Angry Inverter output voltage drop

Hi I am new to this forum so please bear with me. For some years I have been interested in the replacement of HT batteries. I have built an inverter from an unpublished 4047 driven MOSFET circuit. The original contained a 10 va transformer and gave excellent results. Using the same components I have introduced a 1.6va transformer. A 6v input gives approx 130v off load but when connected to radio this falls to 36v and does not work set. Can anyone advise what I am missing here. Many thanks. Merry Christmas.
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Old 16th Dec 2010, 8:45 pm   #2
Station X
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Default Re: Inverter output voltage drop

Volt drop in the transformer windings? Does the set work on batteries?
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Old 16th Dec 2010, 8:57 pm   #3
PJC58-Hythe
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Default Re: Inverter output voltage drop

Have you put a resitive load on the output of the inverter to draw about 13mA to see if the voltage drops to that when the set is connected? If it does it is losses in the circuit - if it doesn't it's most likely there is a fault in the set i.e. leaky capacitors.
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Old 16th Dec 2010, 8:59 pm   #4
evingar
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Default Re: Inverter output voltage drop

Hi Batterymax

And welcome to the forum.

Nothing really to add to the comments already made by Station X. You are more likely to get some further help if you can post a circuit
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Old 16th Dec 2010, 9:07 pm   #5
amp_mangler
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Default Re: Inverter output voltage drop

A circuit would be nice

BUT from the sound of it, there is no compensation circuit, i.e. a circuit that measures the voltage drop and as it compensates, it restores the voltage.

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Old 18th Dec 2010, 5:43 pm   #6
batterymax
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Smile Re: Inverter output voltage drop

Thank you all. I will post a circuit a.s.a.p. but methinks compensation circuit is the key. I am trying to fit this into a B114 package!

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