Audio Description – LED Driving Transformer Efficiency, Part 7
– Clip 1 Introduction – Clip 2 Course Description – Clip 3 Test Parameters – Clip 4 Test Equipment – Clip 5 Overview – Clip 6 Isolation Transformer – Clip 7 Toroid Wave Guide – Clip 8 Toroid Self Triggered – Clip 9 Voltage Increase – Clip 10 CR2032 Power Test – Clip 11 Calculation 1 – Clip 12 Summary – Clip 13 End of Part 7
Clip 1
Clip 1
In this series I will demonstrate the power efficiency of driving LED’s via a new coil on the same core material. As comparison I decided to show you the performance of the Isolation transformer and the new wound toroid core. We use her 40 LED’s, increasing the load by 100% and setting our low benchmark of voltage at 3 Volt. We have to beat the required 100 volt and minimum 100 mA. This array would require 120 volt and 800 mA a total of 96 Watt.
Clip 2
Clip2
Ultra High efficient LED driver
– Compare Soft iron core isolation transformer to Metglas core
– Apply traditional high frequency transformer principle
– Apply Flyback transformer principle
– Compare the power efficiency of both cores
– Demonstrate ultra-low power and voltage driving capability
Clip 3
Clip 3
Test Parameters
1. One Amplifier Module with 2N3055 Transistor
2. Isolation Transformrer
3. Array with 40 LED’s
5. Metglas/Nanocrystal core
Clip 4
Clip 4
Test Equipment
Tools– EA, PS 2000 B, 84 V 5 A, Power supply
– Agilent/Keysight InfiniVision 3000 Series oscilloscope DSOX3014A
– External 19 Inch Monitor for Oscilloscope
– Gossen Mastersix light meter
– Agilent 34450 A 5.5 digit Benchtop DMM
Clip 5
Clip 5
Overview
Clip 6
Clip 6
Clip 7
Clip 7
Clip 8
Clip 8
Clip 9
Clip 9
Clip 10
Clip 10
Clip 11
Clip 11
We integrate our measurements into the formula
Two LED Arrays with 40 LEDs of 3 Volt, 20 mA. Require min 100 Volt
and 100 mA1. Isolation transformer, 7 Volt and 326 mA = 2.282 Watt
At 3 Volt and 153 mA = 0.459 Watt and 250 LX2. Toroid via wave generator, 3 Volt and 7 mA = 0.021 Watt and 320 LX
3. Toroid self-triggered, 3 Volt and 19 mA = 0.057 Watt and 520 LX
Increased to 8 Volt and 22 mA = 0.176 Watt and 980 LXEfficiency is very low on the Isolation transformer. If the ratio to brightness and current draw
is identical than the wave generator trigger would be 61% more efficient to self-triggeredThe CR2032 is drawing only 99 uA but brightness is lower as well.
Clip 12
Clip 12
Summary
The new wound core has a very high efficiency. The larger coil together with the
lower voltage is dropping the frequency into the mains frequency which is prone to
flicker on LED lights. Counter measurements can be applied together with different
coil winding ratios. This setup is well suited for our battery charging circuit and should
give us a higher COP than the achieved 121 % as before. Next will be C-Core testing
together with the so called delayed Lenz effect.