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Power supply voltage regulator circuitRelating to [url="https://www.worldofspectrum.org/forums/discussion/56142/"]this topic[/url] I have managed to acquire this little accessory, which I…
... being handled only by the 7805 voltage regulator in the ZX Spectrum, ... the ‘pre-regulator’ circuit reduces the voltage down to around ... 9V DC, reducing the amount that the 7805 ... a schematic of a pre-regulator circuit:
[img]https ... -
Power supply voltage regulator circuitRelating to [url="https://www.worldofspectrum.org/forums/discussion/56142/"]this topic[/url] I have managed to acquire this little accessory, which I…
... being handled only by the 7805 voltage regulator in the ZX Spectrum, ... the ‘pre-regulator’ circuit reduces the voltage down to around ... 9V DC, reducing the amount that the 7805 ... a schematic of a pre-regulator circuit:
[img]https ... -
+3 - beeper sounds but no AY musicHi guys I am repairing a plus 3 revision 2 board that had no sound at all. Using schematics from https://zxnet.co.uk/spectrum/schematics/ I manage…
... smoothing we have a voltage regulator chip. This uses very ... Spectrum, this is the 7805 voltage regulator. It needs a minimum ... best efforts of the voltage regulator, a small amount of ... The amplifier circuits in the voltage regulator then amplify the noise, ... -
+3 - beeper sounds but no AY musicHi guys I am repairing a plus 3 revision 2 board that had no sound at all. Using schematics from https://zxnet.co.uk/spectrum/schematics/ I manage…
... smoothing we have a voltage regulator chip. This uses very ... Spectrum, this is the 7805 voltage regulator. It needs a minimum ... best efforts of the voltage regulator, a small amount of ... The amplifier circuits in the voltage regulator then amplify the noise, ... -
Climate ChangeThis has been on the News for a couple of days now, including coverage of worldwide rallies calling for more efforts to tackle climate change. I have…
... do it for them) the 7805 voltage regulator with a DC/DC converter ... -
What % of WOSSERS use "old school" tape loading when playing their Speccy games.My guess is .000000001% ( but I might be slightly out on this! ) Do people still enjoy doing it "the old way"?
... a series regulator made from a 7805 three terminal voltage regulator chip. This ... between the input voltage to the 7805 and the 5V ... of heat that the 7805 voltage regulator in the ZX Spectrum ... to replace the existing 7805 voltage regulator with a mini DC/DC ... -
Finding a good (UK) external switch mode power supply for the basic 48k and 128k ZX SpectrumsThis idea has probably "done the rounds" by now . I think I have heard about it a bit late . This thread with look at replacing the original "heavy l…
... regulated SMPSU with an output voltage of 8V to 9V ... passes the “unregulated” input voltage through to the edge connector ... the +9V straight into a 7805 voltage regulator chip (or equivalent). Yes, ... know what the minimum required voltage is.
No ... -
Bit of fun - one change onlyI also posted this on another marque's forum (for their products) to see. Its just a bit of fun really. OK, if you could of made one change to a S…
... onwards, the heatsink for the 7805 voltage regulator was moved from the front ... -
7805 on PlusD needed?I am planning a batch of PlusD interfaces. As I do not have a board design file (for e.g. Eagle), I am redesiging the PlusD schematic in Eagle myself…
... I was wondering: is the voltage regulator (7805) on the PlusD really necessary ... -
ZX Spectrum Pre-regulator DesignCarrying on from the "[URL="http://www.worldofspectrum.org/forums/showthread.php?t=44486"]Issue 2 crashes after about 30 mins[/URL]" thread... [QUOT…
... the heat dissipated by the 7805 internal voltage regulator and heat sink.
Instead, the pre-regulator circuit helps ...
Output voltage from the [U][B]Pre-regulator[/B][/U] circuit ... -
Replacing voltage regulators - need to sanity check a few things pleaseHi Everyone I'm in the process (with a lot of help from some friends at Greenford Computer Club), of giving my three Speccys some much needed prev…
... is a 78S05 5v 2a voltage regulator in the +2, and ... 5v 2a switch mode regulator in order to reduce ... confirm what variant of 7805/78S05 regulators are in ... to replace its legacy regulator, or whether to use ... 2450 5v 1a switch mode regulator. Similarly, I also ... -
how to set voltage regulator to the correct setting ?On the power supply that is broken it says AC adapter INPUT : 230v 50Hz OUTPUT ; 9v 200mA Regulated On the variable voltage adapter i have the…
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On the variable voltage adapter i have there is ... do to set the correct voltage ? -
PC power source and Spectrums.I'm planning to use a basic PC ATX power source (300W) for all my sinclair equipment, but I have two questions: - I've read about some nasty things …
... +12v and relying on the 7805 (I think it will overheat ... +5v and bypass the 7805 or use another voltage regulator to get +9v ... be enough, so what other regulator?
- And (not related ... -
R.I.P. spectrum 48kRecently one of my 48k rubber key (issue 4) machine bit the dust the other day when I tried to power it on. When powering it on, it gave a weird 'bee…
... , full check of voltages, new voltage regulator, new membrane... Also added a ... a better voltage regulator that can be used instead of the 7805 type ... possible to add an additional voltage regulator in case one fails (have ... -
What's this hardware?[URL="http://www2.snapfish.com/slideshow/AlbumID=1351742020/PictureID=39192676020/a=1759991020_1759991020/otsc=SHR/otsi=SPIClink/COBRAND_NAME=snapfis…
... EPROM. There is a 7805 and a 7812 voltage regulator, so the power ... electronic capacitor for smoothing the voltage, nothing special.
Part ... -
The great 128k ConversionWell, I am not sure if it is going to be great. Hopefully it will! This evening, I set about getting my Issue 6A Spectrum Plus working. I suspecte…
... . I had already replaced the voltage regulator back when the machine was ... was soldered in, and the voltage levels tested. All lines were ... having to worry about the 7805 overheating. It isn't pretty ... -
A few mods I've done over the years to my Spec 128k+Hello, Was a bit bored and decided to upload a few pics and sound files from my Spectrum 128k+ I've been tinkering around with over the past several …
... 7805 linear voltage regulator, throw it in the bin and get a switching voltage regulator ... exact same pinouts as the 7805's. This is the one ... -
Switched voltage regulatorIn the past a replacement voor the (hot!) 7805 has popped up a couple of times in various threads. As far as I know, Recom Power Inc. was always ment…
... a replacement voor the (hot!) 7805 has popped up a couple ... -
Microdrive repair - GREAT NEWS!Microdrive repair facts: We know (almost) pure alcohol and cotton swabs are needed a lot to clean the Microdrive head. We know cartridges degrade, so…
... the electrolytic caps at the voltage regulator first.
These have low ... the process I resoldered the 7805 pins and the soldering contacts ... -
Where could I buy a B1367Y transistor in the UK?I'm after a B1367Y transistor, must be T-220 package type that can be mounted to a heatsink. Anybody know where I can buy them in the UK? Tried Googl…
... owner and they have fitted 7805 5V voltage regulator in instead of the ... why they put in a voltage regulator, I'm sure the B1367Y ... . Still I can save the 7805 as it's used in ... -
Frying a 48K ZX Spectrum (revision 4A) with 10 V instead of 5 VHello I got a used zx spectrum. When I opened it up, there was no 5 V positive voltage regulator at the 10 V power inlet. Instead what would be in…
... was no 5 V positive voltage regulator at the 10 V power ... input and output of a 7805 or similar were short cut ... this doesn't step the voltage down from 10 V to ... -
48k Issue 6a Very sick indeed.Hi Guys. I have a 48k Issue 6a board that shows a white screen with grey border. The white screen has three black squares spaced equally on the le…
... I have fitted a new 7805 regulator, socketed lower and upper RAM ... are way off. If the voltage regulator, capacitors, and TR4 and TR5 ... -
Whats wrong with my 128k?The little power converter (the thing with three legs) that sits on the cooling fin was broken, so I bought a new power converter and replaced it. Bu…
The Voltage Regulator you bough (7805), was it a 1A ... a 10A (different type) voltage regulator, but why?
If ... your Regulator is too weak, no ... . Generally I say, 7805 with 1Amp or more ... chance that the damaged 7805 damaged other components in ... -
Whats wrong with my 128k?The little power converter (the thing with three legs) that sits on the cooling fin was broken, so I bought a new power converter and replaced it. Bu…
... type of voltage regulator it was besides that it was a 7805. On ... /> I also had a spare 7805 I took from an old ... -
Spectrum 128kHi everyone, As a long time Speccy fan weaned on the original +2 machine (hence the username!), I'm thinking about finally buying a genuine Sinclair…
The whole point of the heatsink is to keep the voltage regulator cool (just like the much smaller heatsink inside the 48K machine). Without it, the 7805 should go down the drain pretty fast. -
"Unknown disk format"-error on Spectrum +3Hi, I have just gotten around to changing the drivebelt in my newly acquired +3. I tried to format one of the 3" disks I bought on eBay the other we…
... indeed to use a small 7805 type voltage regulator. Anything up to +30V ... -
Best replacement for ZTX650?What is the best replacement transistor for the obsolete ZTX650? I've read that TIP31 will do the trick. Is there a decent equivalent from the BC or …
... has the same transistors and voltage regulator (7805) as a 48k (it's ... -
5v Transformer.I've got a 5v 3A transformer, would this be ok to use with two 3.5 inch floppy drives?
... load (that is to say, voltage is 5V only when power ... about 33% above their rated voltage when no current is being ... better to use a twin 7805 based regulator and power it with ... -
Missing Voltage RegulatorHello all and a very merry 2-days-after-the-speccys-25th-birthday to you all! Okay, I've just received my brand spanking new 48K keyboard membranes …
The voltage regulator's easy - it's a common 7805. You can buy them ... sells components will sell the 7805. They are cheap, and found ... -
TIPP31 transistor questionYesterday I had the time to try and repair a 4S issue 48k spectrum I had. First of all I replaced all the electrolytic capacitors. The tr4 transistor…
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A final question, for voltage regulator (7805) i used one with the ...
