0 Persons are tagged with #tube

#tube

hackaday@xn--y9azesw6bu.xn--y9a3aq
hackaday unofficial

Hackaday Prize 2022: Glass Tube Solar Thermionic Converters

image

Typically, if you want to convert solar energy into electrical energy, you use either photovoltaic (PV) cells, or you use the sunlight to create steam to turn a turbine. Both of these methods are well-established and used regularly in both small- and grid-scale applications. However, [Nick Poole] wanted to investigate an alternative method, using thermionic converters for solar power generation.

[Nick] has been gearing up to produce various styles of vacuum tubes, and noted that the thermionic effect that makes them work could also be used to generate electricity. They are highly inefficient and produce far less power than a photovoltaic solar cell, meaning they're not in common use. However, as [Nick] notes, unlike PV cells etched in silicon, a thermionic converter can be built with basic glassworking tools, requiring little more than a torch, a vacuum pump, and a spot welder.

Experiments with a large lens to focus sunlight onto a 6V3A diode tube showed promise. [Nick] was able to generate half a volt, albeit at a tiny current, with the design not being optimized for thermionic conversion. Further experiments involved electrically heating a pair of diode tubes, which was able to just barely light an LED at 1.7 V and a current of 7.5 uA. The conversion efficiency was a lowly 0.00012%, around 5 orders of magnitude worse than a typical PV cell.

[Nick]'s hope is that he can produce a tube designed specifically to maximize thermionic conversion for energy generation purposes. It's likely there is some low-hanging fruit in terms of gains to be made simply by optimizing the design for this purpose, even if the technique can't compete with other solar generation methods.

In any case, we're eager to see what [Nick] comes up with! We love to see makers building tubes in their own home workshops.

The HackadayPrize2022 is Sponsored by:

Digi-Key

Supplyframe

#contests #science #thehackadayprize #2022hackadayprize #solar #solarpower #thermionic #thermionicconversion #thermionictube #tube #tubes #vacuumtube

Hackaday Prize 2022: Glass Tube Solar Thermionic Converters

Typically, if you want to convert solar energy into electrical energy, you use either photovoltaic (PV) cells, or you use the sunlight to create steam to turn a turbine. Both of these methods are w…

1 Shares
terresemergees@diaspora.psyco.fr
Terres Émergées

Aux débuts du mois d’avril j’ai eu l’occasion d’aller me promener en trois quatre points de France. Le bitume, sous mes yeux, a pu filer sous forme de lignes, et les paysages s’amuser, en surgissant et sautant, à changer rapidement de forme.
C’est lors d’une après-midi particulière que j’ai promené ma conscience des choses le long d’interminables champs de colza jaune, au travers de quelques bois salvateurs et préservés, à coté d’un mur d’enceinte pierreux filant sur des kilomètres afin de préserver quelque ancienne propriété et ce jusqu’à un petit village au canal apaisé mais au fleuve large qui laisse deviner un caractère puissant et maitre de lui même. Des barques à fond plat et des petits bateaux restaient là en silence mais me faisaient bien comprendre que la cohabitation passait par leur présence.
Au bout de cette étape, j’ai trouvé une parenthèse temporelle agréable, une compagnie charmante et quelques sonorités oniriques et roulantes qui m’invitaient à cesser de lutter contre l’envie saine de m’allonger et fermer les yeux quelque temps. La politesse me l’a défendu, la fin de la parenthèse s’est affichée et remerciant mon hôte, j’ai repris la route avec à mes cotés un petit objet violet.

J’ai toujours aimé écouter des 45 tours, mais surtout à la vitesse de 33 tours par minute. Les sons trainants et sourds qui en surgissent sont pour moi très apaisants. Ça ne fonctionne pas toujours, mais je ne me suis évidement pas privé de la faire avec l’album “Carmina” de Merle Bardenoir. Et là, Oh là, plaisir! L’ambiance se ralentit, les sons s’alourdissent et j’y note une énergie soudain plus appuyée, celle du mystère. Le timbre de notre chanteur se métamorphose, et semble tout à coup incarner un Peter Steel français. Chacun garde sa préférence dans sa couleur, mais je me régale du résultat.
Non moins sérieusement, et à la bonne vitesse, ces deux morceaux aux mélodies tubesques me plaisent et je me surprends souvent à en siffloter le refrain au hasard des journées. Et puis quel autre support physique serait plus adapté à de tels sujets, ceux abordés dans ces chansons, si ce n’est le format vinyle à la forme et au mouvement circulaires…
Un bel objet à l’apparence et au contenu soignés.

https://merlebardenoir.bandcamp.com/album/carmina

#voyage #spectateur #paysage #musique #sonorité #mystère #vinyle #merlebardenoir #petersteel #cycle #tube #printemps #vie

Carmina, by Merle Bardenoir

2 track album

1 Shares
hackaday@xn--y9azesw6bu.xn--y9a3aq
hackaday unofficial

This Ham Radio is Unsafe at Any Frequency

image

When we were kids we rode bicycles without pads and helmets. We drank sugary drinks. We played with chemistry sets and power tools. We also built things that directly used AC line current. [Mike] remembers and built one, presumably more to discuss the safety precautions around things that can shock you and not entice you to duplicate it. He calls it The Retro QRP Widowmaker, if that's any kind of a hint. (Video of this unsafe transmitter also embedded below.)

The design showed up from time to time in old electronic magazines. Built on an open board and with no ground wire, the radio didn't need a complex power supply. This wasn't limited to transmitters, either. Some TVs and radios had a "hot chassis." That's why we were taught to touch an unknown chassis with the back of your hand first. A shock will contract your muscles and that will pull your arm away instead of making you grab the electrically active part.

For safety's sake, [Mike] used an isolation transformer to keep from having a disaster. A big resistor drops a lot of voltage to supply the tube in the circuit. There was a neon bulb to indicate if you have your plugs the wrong way around making things dangerous.

We enjoyed [Mike's] excellent code using an old J-38 style key. Not everyone uses a paddle or a keyboard. Nowadays, you don't need high voltages for little transmitters. Also, $50 today is probably worth less than $10 was back then. If you have a hankering for vintage gear, try old transistors, instead.

#radiohacks #hamradio #safety #transmitter #tube

3 Shares