Electrodes Conditioner Conditioning & fill gas Power supply
"mini EPS"
Electrode selection System requirements

Technical Data


Technical Data

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HOTFIL hot filament electrodes

A product of German precision manufacture.
Hot filament electrodes in soft glass enclosure (as Neon/Cold Cathode electrodes) for manufacture of luminous tubes.
Can be spliced by Neon glassbenders like normal neon electrodes; no ring-seals necessary, so no scientific glassblower needed as for normal fluorescent lamp electrode sealing.

Fits almost every application with operating currents from 50 to 700mA.

Types A and B preferrably for use with the HOTFIL "mini EPS" Electronic Power Supply.

Type C for operating with standard 58 W-ballasts*).

Tubes with HOTFIL electrodes can be processed...

  ...without vacuum oven, on Neon pumping systems
    and the HOTFIL conditioner, or...

  ...with a vacuum oven like normal fluorescent
     lamp processing.
   (Manual activating of electrodes necessary)

For all tubes with blue discharge (mercury vapor, no Neon).

Tubes can also be operated in high voltage series circuits without preheat!

Operation of HOTFIL-electrodes on socalled T5-"Multiwatt" electronic ballasts of third party manufacturers (automatic wattage detection) is not yet recommended.
Short term destruction of electrodes is possible.

Therefore use only the recommended Original HOTFIL-mini-EPS.

electrode in action

*)  Electrode type C (equivalent to standard 58 W electrodes) will be available soon.


capped HOTFIL

cap connector

HOTFIL-electrodes with T5-standard caps
simplify the installation remarkably.
Electrode caps can be supplied fitted to the electrode or loose.
Also available: G5 push-on sockets with push-in wire connectors and cable protectors.

Compact, safe connection to HOTFIL-electrodes with T5-caps.
15mm-standard silicone boots(typical neon supply)
are recommended for additional moisture protection.

Electrode selection 

for operation on "mini EPS" 

Important: Always use same type A or B for power supply "mini EPS" and electrodes!

Tube diameter (mm) max. tube length (ft / m) HOTFIL electrode type*)
10 1.6 / 0.5 A
12 2.3 / 0.7 A
15 3 / 0.9 A
15 3.3 / 1.0 B
18 3.6 / 1.1 A or B
20 4 / 1.2 A or B
25 5 / 1.5 B
38 6 / 1.8 B
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HOTFIL conditioner
(check system requirements)

Conditioning unit for manufacture of luminous tubes with HOTFIL electrodes in Neon shops without requiring a processing oven (free of license fees). 

The conditioner consists of a control unit and a high voltage unit. Eight high voltage leads permit the processing (pumping, outgassing, activating etc.) of two tubes of similar dimensions within approx. 15 minutes.

The conditioner can be attached to an existing bombarder/pumping system for Neon/Cold Cathode tubes (see system requirements) within less than 20 minutes.

Standard Neon/Cold Cathode tubes can be processed without removal of the conditioner by flip of a switch.

conditioner front

The HOTFIL conditioner guides the operator step by step through the semi-automatic process and so requiring minimal personnel training. The operator still has constant control over pumping system and bombarder, except for the critical electrode activation, which is controlled automatically. Parameters are checked constantly and error warnings are given by the conditioner. 

The conditioning unit contains extensive safety provisions and thus -if installed properly- is intrinsically safe in any case for bombarder voltages up to 25kV.

high voltage unit

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Technical data HOTFIL conditioner


Dimensions W * H *  D (cm)

Weight, incl. cables (kg)

Power requirements

Length of connecting cable to control unit (m)

Length of high voltage cable (m)

Control unit

18 * 12 * 22


110/230V 50/60Hz 80VA (mains, grounded)



High voltage unit

35 * 25 * 20


max. 25 kV 1.5 A (by Bombarder)



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System requirements for bombarder / pumping system


max. 25 kV open circuit voltage

High vacuum pump  (diffusion/turbo) 

with abs. pressure < 1 * 10-3 mbar at tubulation

and pumping speed > 12 liter/sec at 10-3 mbar

Current control and measurement

in range of 120...400 mA (+/- 20 mA)

Two gas tank connectors with needle valves

for standard labroratory gas cans (12 l)

Access to pushbutton/magnetic contactor 

solenoid coil for interlock with max. 250 V at 5 Amps

Vacuum gauge, 

readout range 10-2...10-3mbar,

delay < 0.5 sec (p.ex. Pirani / thermocouple gauge)

"Hard" switching of bombarder (no "Softstart")

Filling gauge, gas type independent,

range 1...30 mbar (< +/- 0.5 mbar), 

delay < 0.2 sec. (p. ex. oil filled U-gauge)

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HOTFIL conditioning gas
HOTFIL fill gas

Inert gas mixtures with optimal composition for semi-automatic manufacture of luminous tubes using HOTFIL electrodes and HOTFIL conditioner.

The gases are supplied in standard laboratory aluminium cans (1 liter at 12bar pressure = 12 liters content)


gas bottle


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HOTFIL power supply
"mini EPS"


Electronic Power Supply "mini EPS" with active, regulated PFC (Power Factor Correction) for individually manufactured HOTFIL tubes.

Intelligent flicker-free quickstart with tube protection.

Automatic shut-off on open circuit, filament breakage, tube breakage, overtemperature and overload.

Extremely small - ideal for channel letters.

Completely sealed and watertight - IP65

Can be used outdoors without additional enclosure.

Constant output current (=brightness) independent on tube length.

Installs like standard-fluorescent lamp ballasts.
Cable length input and output: 1.5m with prepared ends

Output voltage less than 1000 Volts, thus no hassle with high voltage regulations. Can be installed by every licensed electrician.

The "mini EPS" types A and B are designed especially to fit with HOTFIL electrode types A and B, respectively.


.image eps

dimensions eps

Technical data HOTFIL mini EPS

  Max. power per tube on 230 V a)  W < 28
  Output current constant  (mA) 180
  Supply voltage (V) 220...240
  Mains frequency b) (Hz) 0 / 50...60
  Current consumption at 230 V a)  (A) 0.11
  Battery voltage, specified c) d) (V) 176...264
  Output frequency approx. (kHz) 45
  Power factor to line 0.95
  Preheat time (sec) 4
  Operating temp range (F)  + 5...+ 140 
  cable length (input & output) 1.5m (5ft)
  wire type input H03VV2G0.75 color:white
  wire type output H05VH-F2G0.5 color:white
  Protection / markings IP65; CE
a) Values for tube lengths according electrode selection

b) DC supply (emergency lighting) 220 V = 

c) Start voltage min. 186 V, operates on low as 176 V 

d) Application: general and emergency lighting according to VDE  0180 


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