Little Monkey


... ruder

(discontinued 2015)

Filthy Edna 1 caving lamp (discontinued)

Filthy Edna 1





Filthy Edna

EDNA - Basic Operation


EDNA has 2 LEDs, and 5 power settings, in very simple to use group of 3 core settings, plus 2 additional settings.


The main LED (Cree XL-L2 5000k) has 4 power settings. 3 settings in sequence LOW, MEDIUM, HIGH (and back to LOW), operated by push (and release) switch to step through these settings. This simple sequence incorporates a 3 second next push OFF feature. If EDNA has been running in any setting (low, med, high) for more than 3 seconds, the next operation of the switch will be OFF.


There is also a VERY HIGH setting (push and hold switch for around 1 sec). This can be selected from any of the 3 core settings (low, med, high). At next push of switch EDNA will return to the mode from which it was previously selected (low, med, high).


The pilot LED (4000k) is driven independently and provides a VERY LOW, constant output setting. To operate this setting, push and hold the switch from lamp off. There is also a low power red LED used to indicate battery charge. This LED blinks 1-5 times, when the pilot LED setting is selected, and is just visible on back of hand.


EDNA runs the main Cree XM-L2 LED, on highest power setting, at constant 3A LED current; around 1000 lumen (dependant on operating temperate; 1050 lumens @25degC to 925 lumens @85degC). This is the maximum output that is realistically achievable using 2 series cell 7.4v buck regulated architecture, in order that full output is available though out the battery discharge profile. This is basically because of battery voltage droop under load (and its relationship with buck circuits, forward LED voltages, and critical voltages of li-ion cells). We always advice using good quality cells. However, as we have little or no control over user cells, we have incorporated Intelligent Power Ramping and Battery Management software (see section below).


EDNA Start-up


When connected to batteries, EDNA will start in VERY LOW pilot LED setting. This should ensure that should switch failure ever occur, that some light is always available, simply by connecting batteries. Next switch push is off. When EDNA is off, but connected to batteries, red indicator LED will blink periodically. When connected to batteries, but switch off, parasitic battery drain is negligible, just 0.07 mA.


EDNA - Intelligent Power Ramping (applicable to maximum power setting)


On maximum output setting, EDNA circuitry will pull around 1.8A from batteries in order to maintain a constant current of 3A at LED. This is a readily achievable level. We have been using Sanyo and Panasonic cells during testing, and lamp can deliver maximum output close to the end of battery discharge.


However, we have limited control over users choice of cells. Even running just one XM-L2 LED at 3A current can cause battery voltage to droop significantly. In order to accommodate this, EDNA incorporates Intelligent Power Ramping software (on the maximum 3A output setting).


When maximum output setting is selected, EDNA will ramp up to 3A LED current over a short period (< 1 second), while monitoring the impact of this on the battery. If batteries are depleted (or just junk), and 3A LED current cannot be achieved, EDNA will maintain a reduced power level, in order that voltage will not droop below the essential shut off level of the li-ion batteries.


If the full 3A LED output setting cannot be achieved, then lamp will give a momentary blink, so that user will know that it has not reached maximum output (and is holding at a reduced level). As the battery depletes further, the light output level will be reduced accordingly. This notification blink can occur either when you initially select maximum mode, or later if you have been running this setting and battery can no longer sustain full 3A output.


Battery Discharge Management


EDNA is constantly monitoring the level of battery charge and performance under load. This is used to provide user feedback about level of battery charge. EDNA feature a low power red LED, to indicate battery charge. This red LED will blink 1-5 times, when pilot LED is selected, just visible on back of hand. 1 flash battery very low, up to 5 flashes fully charged.


When battery charge is very low, EDNA will automatically shut off settings, one at a time, from high to low. Whenever EDNA steps down due to battery condition, it will provide a momentarily blink (single blink) so that user is aware.


E.g. if you run EDNA on high setting, it will eventually (blink and) drop to medium, then low, and then very low. If however you run EDNA on medium setting, then the first (blink and) drop will be to low setting, removing both the medium and high settings together. Similarly, if you run EDNA on low setting then the first, and only drop will be to very low setting. In all examples, MAXIMUM 3A setting is removed at the first step down.


EDNA also features Critical Battery Voltage Protection, set to shut off lamp at appropriate level. If using UNPROTECTED cells this protection is crucial to guard against over discharge. If using PROTECTED cells, either batteries or lamp will shut off (dependant on the voltage level set on the batteries protection circuit, versus the critical level set on EDNA).


Thermal Management


EDNA incorporates thermal management. If lamp temperature is too high then EDNA will fast blink (strobe) for a few seconds, and step down to LOW setting. Under normal use, thermal management is only likely to be apparent on maximum VERY HIGH setting.


In test environment (16 degC, minimal air movement, lamp static) we have been running HIGH setting without activating thermal management.






Edna Lamp Setting


Duration (3400mAh cells)

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Very Low



Edna Operation