practical high voltage power supplies ian white, gm3sek click to step through the presentation
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Practical High Voltage Practical High Voltage Power SuppliesPower Supplies
Ian White, GM3SEKIan White, GM3SEK
Click to step through the presentationClick to step through the presentation
Practical High Voltage PSUs
• Safety + Reliability
• Practical circuits and components
Safety + Reliability
Thousands of amateurs use HV safely,every day.
So can you!
But your first big mistake will be your last, so…
Always think about what you’re doingand you’ll be fine.
DON’T MAKE MISTAKES!
Safety + Reliability
Good safety habits:
• Multiple barriers against failures and accidents.
• NEVER be only one fault away from danger.
• ALWAYS unplug from the mains.
• ALWAYS discharge HV circuits before touching.
• Multiple earth bonding – very important.
• ALWAYS be thinking what could possibly go wrong…
and then prevent it!
1. Defence in Depth.
Safety + Reliability
Good safety habits:
1. Defence in Depth.
2. Build safety into hardware. • Don’t rely on ‘being careful’… because one day you will drop your guard.
• Use good quality components and construction.
• Greatest risk when testing and repairing.
Use safety covers inside (clear acrylic sheet).
Safety + Reliability
Make these into your way of life:
1. Defence in Depth.
2. Build safety into the hardware.
3. Don’t ever stop thinking!
Safety + Reliability
Reliability – for DX and contesting
Building reliability into the hardware: • Good quality components and construction.
• Under-run all components.
• Check all component ratings.
• Use cooling fans.
Practical High Voltage PSUs
Safety + Reliability
• Practical circuits and components
Circuits and Components
Circuits and Components
Mains
Circuits and Components
Transformer
Circuits and Components
Rectifiers + capacitors
Circuits and Components
HV+ output
Circuits and Components
HV-minus return
Circuits and Components
Mains
Circuits and Components
Circuits and Components
Transformer
Circuits and Components
Transformer
Circuits and Components
Transformer
Circuits and Components
Transformer
Circuits and Components
Circuits and Components
Circuits and Components
Circuits and Components
Rectifiers + capacitors
Bridge rectifieris best!
About 30uF
Circuits and Components
HV+ output
Surge limitingresistor
(“Glitch resistor”)
HV socket
• Coaxial
• SAFE connector!
• Earth bonding
Circuits and Components
HV-minus return
Why a separateHV-minus return?
Chassis earthChassis earth
Circuits and Components
HV-minus return
Anode current
Anode current
Grid current
Circuits and Components
HV-minus return
5-pin XLR socket:
• HV-minus (duplicated)
• Earth (duplicated)
• HV control input
• Connector shell also earthed. Important safety precautions.
HV won’t turn on unless this is plugged in.Chassis earth
Circuits and Components
Practical High Voltage PSUs
Safety + Reliability
Practical circuits and components
For more details…
• Radcom January-February-March 2009
• The ‘In Practice’ website:http://tinyurl.com/inpractice
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