What\'s a wizard???
Hi guys,
I have seen various posts in regards to the wizard converter and of course now the next generation Wiz2. For those unfamiliar with the wiz, I think a little background is advisable. I will relay what I know and recall, to the best of my knowledge. The best of my knowledge may fall short of reality so please chime in and make corrections where needed! /ubbthreads/images/graemlins/blush.gif
Wayne started his drivers with the max series. These were and are voltage regulated drivers which boost the supplied voltage up to higher outputs to the LED's. His next development was the BadBoy converters which are a boost circuit that provides a set constant current to the LED. For various reasons, the LED manufacturers suggest a constant current drive as the preferred method for driving LED's.
Some time after SureFire came out with the KL1 shich has a buck/boost constant current driver, Wayne came up with the wizard. A buck/boost driver can accept voltage both above and below the voltage required by the LED and it, in the case of a constant current buck/boost driver, can either boost the voltage up or step the voltage down while continuing to provide a constant current to the LED. Unfortunately, the versatility of such drivers comes with a cost which turns out to be efficiency. This loss in efficiency can be considered in terms of reduced runtimes but in the case of these LED lights, I think it is important to consider where this "wasted" energy goes! Yup! Heat!
To my limited knowledge, the KL1 is the only commercially available LED light with a buck/boost driver. It provides a constant current in the mid 300 mA's to the LED. Wayne's Wizard, with an output set at 400 mA is very comperable and can handle an even greater range of input voltages. The inefficiencies wasted in heat, at these drive levels can be handled by reasonable thermal considerations and relief in good flashlight designs. Unfortunately, with the 5W LED's and now the Lux III's there are needs and demands for more current and power than the wizard is capable of. A 611 mA output for a LuxIII or 1 watt LED has been accepted as the maximum output to demand from the wizard.
Although limited in eficiency, the wizard offers some real advantages in the realm of mixed power supplies and battery configurations. Why don't we see more of them in use and why don't I offer them in the ALeph system? Well the answer is real simple! They are a PITA to install and configure within the E-Can or ES-Can of the LE. The other primary reason is many want more than 611 mA driving their LED's. I won't get into the mechanics of why they are a PITA but it has to do with the fact that their current configuration requires considerable extra effort. /ubbthreads/images/graemlins/tongue.gif
Before I move away from the existing wizard converter, I would like to point out one host and consideration that I think is ideal for the wizard but to my knowledge, no one has exploited it. This would be the use of the wizard in a McCapsule for the LongBow. A wizard 500 with good LuxIII in a McCapsule would give you a light engine for the LongBow that could handle any of the various powerpaks provided by LongBow with them loaded with any types of batteries that would fit! NiMH, ALk, Lithium, 2x Li-Ion.............. /ubbthreads/images/graemlins/thumbsup.gif
Now there is a new wizard about to hit the scene. I believe Wayne is calling it the Wiz2. It's a buck/boost constant current driver and this is why it is called a wizard. Its similarity with the oldr wizard ends there though! This driver is considerably more efficient and it can handle enough power to drive a LuxIII at full current! It does have some significant limitations though and these need to be understood. It will shut down when the voltage supply drops below about 2.75 volts. This was an intentional design consideration for the chip and based on a redundant and dependable means of protecting Li-Ion cells from over discharge. I have been led to understand that even though a Li-Ion cell will power off at a set low voltage, it can still provide low current on demand and over time, it can be discharged to levels that are destructive to the cell. The Wiz2 has an upper voltage limit around 6 volts; limited both as Vin and Vout; no 5W's will be driven by the Wiz2. It is also important to note that a single CR123 Lithium cell under the power demand of high output (1000mA) will NOT be up to the task; its voltage will drop below the 2.7 V shut off.
So what is the Wiz2 good for? It's good for any battery supply that will provide from say 3 to 6 volts and it will drive a LuxIII at high currents and with remarkable efficiencies. One might say that with free power from rechargeable cells,who cares about efficiency. Well, don't forget that power wasted in inefficiency is power let out as heat! If you are driving a LuxIII at 1000mA, the LED itself is generating significant heat that needs to be released. Adding heat from the converter's inefficiency is not helping the thermal picture.
The good news is that the Wiz2 is a buck/ boost converter. In terms of using a two stage resistor tail switch, thebad news is thatthe Wiz2 is a buck boost! /ubbthreads/images/graemlins/icon15.gif A resistor based two stage switch is most efficient when coupled with a step down(buck) converter that will simply move into direct drive once the Vin drops below the Vf of the LED. In the case of the Wiz2 knocking it out of regulation is not trivial and it can be done so with limited success and at a cost of efficiency.
Anyone wanting to use the Wiz2 and also desiring a two level output should cosider that the Wiz2 is doing best in the high level and you should identify your output level based on using the high level as the primary level. This is easy for those who want max brightness! /ubbthreads/images/graemlins/grin.gif
Below, is a runtime graph of a Wiz2 1000 on 2x123 driving a TW0J in an Aleph3:
Now I have been trying to find a good resistor value to try to get some benefit from a low level, even if efficiency is out the window. For the particular LE I am testing, I now believe this resistance value is somewhere between 12 and 15 ohms and likely close to the 12 ohms. I did a run time graph last night and you can see that there is some goofy instability but the bottom line is that there is a net gain in runtime and you do have a lower level of output:
There is one added bonus from the 2.7 volt shut off of the Wiz2. In the example of low level runtime above, the light shut off on low after 5 hours. There was no light coming out; nada. However, when I pushed the switch into high level, I got 4500 lux out of the light! In other words, at some point, just like the SF L1, you will know your batteries are about shot because low level will not function but you still have high output. This rudamentary low battery indicator might provide real value to some users. Now this was one test case and I suspect the reality of using these lights intermittantly on both high and low levels will likely deviate from the performance indicated by these graphs. I am clueless as to what the deviation might be. /ubbthreads/images/graemlins/icon3.gif YMMV!!
One last comment on the low level runtime: The inefficiencies again are manifest as thermal waste. It was interesting to touch the Aleph3 and find the head of the light relatively only warm with the tail cap noticibly hotter! The ambient temperature in my garage at the time was in the high 80's F and this didn't help anything! Especially the tester!! /ubbthreads/images/graemlins/icon15.gif
OK, I shot my wad here on thewizard drivers! /ubbthreads/images/graemlins/nana.gif
Hi guys,
I have seen various posts in regards to the wizard converter and of course now the next generation Wiz2. For those unfamiliar with the wiz, I think a little background is advisable. I will relay what I know and recall, to the best of my knowledge. The best of my knowledge may fall short of reality so please chime in and make corrections where needed! /ubbthreads/images/graemlins/blush.gif
Wayne started his drivers with the max series. These were and are voltage regulated drivers which boost the supplied voltage up to higher outputs to the LED's. His next development was the BadBoy converters which are a boost circuit that provides a set constant current to the LED. For various reasons, the LED manufacturers suggest a constant current drive as the preferred method for driving LED's.
Some time after SureFire came out with the KL1 shich has a buck/boost constant current driver, Wayne came up with the wizard. A buck/boost driver can accept voltage both above and below the voltage required by the LED and it, in the case of a constant current buck/boost driver, can either boost the voltage up or step the voltage down while continuing to provide a constant current to the LED. Unfortunately, the versatility of such drivers comes with a cost which turns out to be efficiency. This loss in efficiency can be considered in terms of reduced runtimes but in the case of these LED lights, I think it is important to consider where this "wasted" energy goes! Yup! Heat!
To my limited knowledge, the KL1 is the only commercially available LED light with a buck/boost driver. It provides a constant current in the mid 300 mA's to the LED. Wayne's Wizard, with an output set at 400 mA is very comperable and can handle an even greater range of input voltages. The inefficiencies wasted in heat, at these drive levels can be handled by reasonable thermal considerations and relief in good flashlight designs. Unfortunately, with the 5W LED's and now the Lux III's there are needs and demands for more current and power than the wizard is capable of. A 611 mA output for a LuxIII or 1 watt LED has been accepted as the maximum output to demand from the wizard.
Although limited in eficiency, the wizard offers some real advantages in the realm of mixed power supplies and battery configurations. Why don't we see more of them in use and why don't I offer them in the ALeph system? Well the answer is real simple! They are a PITA to install and configure within the E-Can or ES-Can of the LE. The other primary reason is many want more than 611 mA driving their LED's. I won't get into the mechanics of why they are a PITA but it has to do with the fact that their current configuration requires considerable extra effort. /ubbthreads/images/graemlins/tongue.gif
Before I move away from the existing wizard converter, I would like to point out one host and consideration that I think is ideal for the wizard but to my knowledge, no one has exploited it. This would be the use of the wizard in a McCapsule for the LongBow. A wizard 500 with good LuxIII in a McCapsule would give you a light engine for the LongBow that could handle any of the various powerpaks provided by LongBow with them loaded with any types of batteries that would fit! NiMH, ALk, Lithium, 2x Li-Ion.............. /ubbthreads/images/graemlins/thumbsup.gif
Now there is a new wizard about to hit the scene. I believe Wayne is calling it the Wiz2. It's a buck/boost constant current driver and this is why it is called a wizard. Its similarity with the oldr wizard ends there though! This driver is considerably more efficient and it can handle enough power to drive a LuxIII at full current! It does have some significant limitations though and these need to be understood. It will shut down when the voltage supply drops below about 2.75 volts. This was an intentional design consideration for the chip and based on a redundant and dependable means of protecting Li-Ion cells from over discharge. I have been led to understand that even though a Li-Ion cell will power off at a set low voltage, it can still provide low current on demand and over time, it can be discharged to levels that are destructive to the cell. The Wiz2 has an upper voltage limit around 6 volts; limited both as Vin and Vout; no 5W's will be driven by the Wiz2. It is also important to note that a single CR123 Lithium cell under the power demand of high output (1000mA) will NOT be up to the task; its voltage will drop below the 2.7 V shut off.
So what is the Wiz2 good for? It's good for any battery supply that will provide from say 3 to 6 volts and it will drive a LuxIII at high currents and with remarkable efficiencies. One might say that with free power from rechargeable cells,who cares about efficiency. Well, don't forget that power wasted in inefficiency is power let out as heat! If you are driving a LuxIII at 1000mA, the LED itself is generating significant heat that needs to be released. Adding heat from the converter's inefficiency is not helping the thermal picture.
The good news is that the Wiz2 is a buck/ boost converter. In terms of using a two stage resistor tail switch, thebad news is thatthe Wiz2 is a buck boost! /ubbthreads/images/graemlins/icon15.gif A resistor based two stage switch is most efficient when coupled with a step down(buck) converter that will simply move into direct drive once the Vin drops below the Vf of the LED. In the case of the Wiz2 knocking it out of regulation is not trivial and it can be done so with limited success and at a cost of efficiency.
Anyone wanting to use the Wiz2 and also desiring a two level output should cosider that the Wiz2 is doing best in the high level and you should identify your output level based on using the high level as the primary level. This is easy for those who want max brightness! /ubbthreads/images/graemlins/grin.gif
Below, is a runtime graph of a Wiz2 1000 on 2x123 driving a TW0J in an Aleph3:
Now I have been trying to find a good resistor value to try to get some benefit from a low level, even if efficiency is out the window. For the particular LE I am testing, I now believe this resistance value is somewhere between 12 and 15 ohms and likely close to the 12 ohms. I did a run time graph last night and you can see that there is some goofy instability but the bottom line is that there is a net gain in runtime and you do have a lower level of output:
There is one added bonus from the 2.7 volt shut off of the Wiz2. In the example of low level runtime above, the light shut off on low after 5 hours. There was no light coming out; nada. However, when I pushed the switch into high level, I got 4500 lux out of the light! In other words, at some point, just like the SF L1, you will know your batteries are about shot because low level will not function but you still have high output. This rudamentary low battery indicator might provide real value to some users. Now this was one test case and I suspect the reality of using these lights intermittantly on both high and low levels will likely deviate from the performance indicated by these graphs. I am clueless as to what the deviation might be. /ubbthreads/images/graemlins/icon3.gif YMMV!!
One last comment on the low level runtime: The inefficiencies again are manifest as thermal waste. It was interesting to touch the Aleph3 and find the head of the light relatively only warm with the tail cap noticibly hotter! The ambient temperature in my garage at the time was in the high 80's F and this didn't help anything! Especially the tester!! /ubbthreads/images/graemlins/icon15.gif
OK, I shot my wad here on thewizard drivers! /ubbthreads/images/graemlins/nana.gif
