Hallo zusammenIch brauche Hilfe beim Identifizieren von L4 auf dem SchaltplanMusste die Spule abwickeln und es messen. Der draht ist 32-33 cm lang und 0,6 mm dick. Der Kern ist 6,3 mm hoch, der innendurchmesser beträgt 8 mm und der außendurchmesser 12,3 mm.Kennt jemand den richtigen Wert für diese "Doppelspule"?
Hallo Besucher, der Thread wurde 2,5k mal aufgerufen und enthält 17 Antworten
letzter Beitrag von boelle am
brauche Hilfe beim Identifizieren "Doppelspule"
- boelle
- Erledigt
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Moin,
L4 Line Filter Assy C 251701-01hier gefunden:http://www.zimmers.net/cbmpics/cbm/c64/C64ServiceManual.txt
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Hallo
Ja aber leider sagt es nicht, was der Wert in mH sein sollte
Ich hätte ein LCR-Meter hier im Labor .....
Durchmessen dauert ca. 1 min ... nur die Spule hab' ich nicht ....
Wenn Du sie mir schickst kann ich die gerne durchmessen und zurückschicken .... -
'Amperes' is the usual meassurement für those line filters. All other parameters have been taken care of by the engineers... and the µH are the least interesting of them. What you would need: The number of windings, the 'Ampere-windings' of the core (a constant that tells you how 'magnetically strong' the ferrite material is) and the frequency response of the ferrite (that tells you how good the coil will be in blocking high frequency 'dirt'; might be a lesser problem on the '64 against more modern stuff?)
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The special thing about these double-coils is their wiring and their position in the schematic: These are DC-filters that - by design - can never push the magnetic material into saturation. The trick is that current "to" the sink is going through the first wire, causing a "positive" magnetic field, which is amplified by the ferrite material. The return current, which is 100% equal by the laws of physics, goes through the second wire and causes a negative magnetic field of "almost equal" magnituge ("almost", because the distance to the ferrite material is never 100% equal).
The sum of both magnetic fields is always "near zero", hence the ferrite material can be cheap, and not affect the performance of the device.
The German word is "stromkompensierte Drossel" - not sure what the correct English term is, but it may be something like "current-compensated coil".
Jens
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the crystal just confuses me as what freq it should have... is it the same for both PAL and NTSC ?
No. 14.31818 MHz for NTSC, 17.734472 for PAL (taken from the BN/E schematic but the same for all VIC-II and VIC-IIe systems)
The coils are a bit hard to find for 'end users' like us; it's not what 'makers' (to use that ultra-modern term) usually play with. Maybe look at supply houses like Mouser or RS?
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Nächstes mal zählst du am besten mal wie viele Windungen der Draht um den Kern hat. Das wär vielleicht jetzt das Wichtige daran gewesen, wenn man die Spule hätte berechnen wollen.
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The German word is "stromkompensierte Drossel" - not sure what the correct English term is,
Afaik "Choke"
