Forum

Voltage increasing via regulator

A somewhat confused question if I may say so Eric!😲 You can't 'regulate up' only down. The regulator's job is to produce a constant lower voltage from a range of higher voltages. I often use one to produce 5V for the RX and servos from a 12V SLA drive battery. A little 3 legged device (type LM7805) which looks just like the power FETs in a high current ESC. My version of a UBEC! 😉 What is this 'regulator' you have? Type number? Manufacturer? Photo? To get 12V from 7.2V you would need to use a Voltage converter (also known as an inverter). This works by converting the DC input from the battery to an AC voltage which can then be increased using a transformer. More elegant (and expensive!) versions use a transistor and amplifier. This uses hi-power transistors instead of the transformer. The AC output of the transformer (or amplifier) is then rectified back to DC. All this is very inefficient which is why it is normally only used for very light currents, where the losses are not so significant, and when there is no other alternative, not often the case! You can't beat the physics and you will never get the same power out that you put in. This leads to a basic design question:- What is the total current consumption of the load? I.e. the motors. A simple example:- Let's say that at 7.2V the motors draw 10Amps total, i.e. 72W (or VAmps). Assuming a utopian 100% efficiency at 12V this would equate to 6A. Due to the three stages of conversion; DC to AC, transformation / amplification of AC to 12V, AC back to DC, you'll probably be lucky to get an efficiency of around 60% to 70%. Thus if you stick 720W in you'll get around 430 to 504W out. Not much of a gain is it!🤔 Your battery would be exhausted in about 2/3 the time it is now 😡 If your motors draw more than 10A the problem just gets worse. So what is it you really want to do? If you just want to up the volts to your motors stick a 12V SLA or an 11.1V LiPo (3S) in and hope that you don't cook your motors! Frankly I don't really know why you're bothering, tugs aren't sprinters! If you want more pulling power with the existing setup try experimenting with prop sizes and pitch. Will probably achieve much more than fiddlin' about with voltage converters. BTW: All this assumes that the RX has it's own separate 5V battery supply or from a BEC in the ESC. Some clarification needed from your side. Cheers, Doug 😎

6 years ago by RNinMunich

Forum

Launch ELAINE,

Thanks for the 'electricals' pics! Definitely a triple XXX Home brew. DCC90; would appear to be an RF double triode. Used as an RF amplifier and/or . Possibly in the UHF band. Trying to find some decent specs on it. If yours is dud there are still some around for a tenner or so; https://www.ebay.com/itm/DCC90-Mullard-Valve-Tube-Used-Old-Stock-1-pc-N17-/192372081346 Must dig around in the cellar; somewhere I have a box of valves too! (Surprise surprise! I hear you say😉) Cheers, Doug 😎 PS Here some history and data on the bottle. Up to 40Mhz apparently. http://www.r-type.org/exhib/aaa1001.htm PPS Valve data now attached in the PDF😊

6 years ago by RNinMunich

Response

Seeing the light

Hi Peter, attached the pinout of the 555 and a circuit for an astable giving a square wave output suitable for a lamp flasher. Frequency (flash rate) is defined by R1, R2 and C. The bigger the 'C' and/or R1 the slower the rate. R2 defines the discharge rate. Therefore the ratio of R1 +R2 to R2 defines the ratio of On / Off times! A little experimentation needed. You can put your pot in place of R1 for some flash rate (F)adjustment. F=1/Cx(R1+2xR2). If you want to get really 'snazzy' you can use the 555 in monostable mode (pic 3) and use the pulse output from an RX channel as the trigger input. You may need to add a series capacitor and a resistor to ground (try a 10K to start with) to slow the trigger down a bit and experiment with the capacitor, a small electrolytic or Tantalum. it helps if you have an oscilloscope for such experiments! A cheap analogue 100Khz or 1Mhz job would do. The astable version is simpler, just put a remote controllably switch e.g. transistor switch board or, even simpler, just a microswitch mounted on a servo😉) in series with the Vcc (+ supply) to the timer chip. It takes longer for the first flash after switch on to occur as the cap has to charge up from 0V to 2/3 Vcc. After that only from 1/3 Vcc to 2/3. Ratio of ON time to OFF time depends on R1 and R2. ON=Cx(R1+R2), OFF=CxR2. Happy soldering and Flashing 😲, cheers, Doug 😎 PS: are your 555s bipolar or CMOS? Makes a difference! Bipolar types only drive the output to Vcc-1.7V. CMOS types drive the output to full Vcc😊 PPS: One other point! is your 'Blue Lamp' a bulb or an LED? If an LED you will need a resistor in series with the output to limit the current to a max of about 30mA. Start with 1KOhm, if too dim go down to around 220/270Ohms.

6 years ago by RNinMunich

Media

none

Experimenting with steam flash boiler and it looks promising!!! Better make a pump next instead of the syringe but I don't expect the little will cope. if it doesn't will make a small electric one. Need an ice breaker today !!! Les

6 years ago by lesliebreame

Forum

New to the game

Hi Marky I have the Deans 4' glass fibre hull steam picket boat, uses either electric or a Miranda Twin steam plant. Mine is the gunboat version as against the Admirals barge, but all capital ships of the period have several picket boats so you have a wide choice. The bands on the funnel signified the boat number 2 bands, boat 2 etc. Good luck wth the builds Dave

7 years ago by Dave M

Media

Jane

One of my Old Trafford paddle steamers enhanced by my mate Duncan Laurimer and sailing on the put up pond at Tilford Rural Life Centre yesterday. Good fun was had by all !! The boiler is tablet fired [3 halves ] and is half filled with 65ml of water. Engine is single with 16:1 spur gearbox. Les Breame

7 years ago by lesliebreame

Response

''Sweet Sue''

Hi Kevin Yes that's what I do. I am always amazed at the power the generates and once rotating very little steam is required to maintain speed. Then again it's not for windy or rough conditions. I would try gradually reducing the pressure until the engine show signs of stopping and then increase by a couple of psi to ensure safe running. You do not need to run the boiler at its max rated pressure when the escape valve will be opening just at a level that replaces what the engine uses. Can we have another video with the steam whistle sounding? Dave

7 years ago by Dave M

Response

''Sweet Sue''

Looking good Kevin. I have a similar and it runs well on 20psi max and gives about half an hours steaming on a similar sized boiler. Dave

7 years ago by Dave M

Response

X System

Hi Edward, its a fine balancing act of electrolysis to hydroide gas, compression then ignition but utillising vacuum formation as an assisting force to the power stroke so effectively making it a one stroke which sounds odd.still in development ive tried turbine, pistons and hydraulic recoil as end movers but the best seems to be the straight reciprocator. its scary,how the hell can they tax water??? cheers Neil.

7 years ago by mactin

Forum

POLARITY

Hi, I´m back . As I can see .. two-pole socket is designed for insertion of a crystal, ( quartz prism 35 MHz) not as a supply battery - this also may cause misunderstandings. This arrangement was customary for facilities of 80 and 90 years of the last century with interchangeable crystals. wishing success Tom

7 years ago by tomarack

Response

Naval pinnace or Picket boat completed

Nice clean model. Clearly the No 1 boat for ceremonial and Captains use. I built the Deans version which is a 48" hull giving a scale of 1/12. I have sailed with electric power but not with my Miranda boiler and twin . I has steamed on my paddling pool at home but I am waiting for a calm day to sail on the club lake. Be good to see your model under srteam on the lake. Dave

8 years ago by Dave M

Media

Duke of Devonshire

My own design double acting twin . Running under steam for the first time. Steam pressure down to 5psi. By the bench on the floor a derelict fire boat, re build one day. installed in Duke of Devonshire.

9 years ago by hammer

Media

Victoria

This is Victoria, she was built from a Krick kit about 4 years ago, steam powered with a Maccsteam boiler and an SVS 10mm bore x 11mm stroke . She is currently taking a well earned rest after 3 years hard work, out 3 days a week, weather permitting. Undergoing boiler cleaning, engine overhaul and a bit of patching up of the woodwork.

10 years ago by Nickthesteam

Directory

(Other) Victoria

Victoria is built from a Krick kit, and has a Maccsteam 3.5 inch horizontal boiler fired by Propane/butane mix. The engine is a 10mm bore x 12 mm stroke SVS . Radio is Futaba 6EX 2.4 ghz. (Motor: SVS 10mm x 12mm) (ESC: Maccsteam Boiler) (8/10)

10 years ago by Nickthesteam

Blog

engine room

Twin double acting , .75" bore .5" stroke, geared down 3 to 1. The boiler 2.5" diameter 6" long by two interconnected. fire tubes 28mm reducing to 22mm half way, ten cross tubes 8mm in each. Silver gas regulators up front, two required to balance the jets, as only one gas cannister. The separator not connected yet. All my own design & manufacture. Except the pressure gauge & cannister tap.

10 years ago by hammer

Forum

Age of steam

Whilst it may be possible to do this is something for the expert to try. Simple model steam s are quite safe to use in their intended form and used correctly should pose few problems for the user. However they are simple and lack many of the safety features of their bigger models. I suggest you join a model boat club with steam testing facilities and get expert help in addressing your requirements. Sorry if this comes across in a negative fashion but for your own safety and the public's generally this is not something you should try yourself.

11 years ago by Dave M

Directory

(Naval Ship) Steam Picket Boat

Built from a Deans marine hull and plan. Steam boiler and twin made by fellow club member John Moore (of Bogstandard fame). Also sails with a large electric motor (1/4 shaft) from Model Motors Direct, fits in place of the steam unit with 12v sla and Electronize ESC. Made all the brass fittings and has fiberglass front casing and engine cover. The rudder is linked to the wheel which turns with the helm. (Motor: Twin ) (8/10)

12 years ago by Dave M