Wednesday, 16 August 2017

Unstable / Surge Voltage for XL6009 Buck Convertor

Unstable / Surge Voltage for XL6009 Buck Convertor

I am new to electronics, and this small boost convertor has me baffled. It displays some weird behaviour. One sets the voltage using the small brass screw, but then if you watch and wait the voltage climbs from the set voltage, 5 Volts in my case up to 28v or higher. I have also observed the same behaviour when setting the boost converter to 10v.

This has resulted in me destroying a bluetooth amplifier, because after setting the voltage at 5V, and connecting the voltage climbed to 28v and killed the amplifier board (PAM8403).

I am powering the XL6009 board, with a headway 8ah LIfePO4 battery at 3.9V, which is rated for 100A output. So I do not think insufficient power is the problem.

If you have had any joy with this sort of thing O would appreciate some help.

Friday, 14 July 2017

Make a Portable Speaker with PAM8403 Amplifier

Make a Portable Speaker with PAM8403 Amplifier - Intro

Do you have an old speaker or two hanging around in the garage or loft? Would you like to make a kick @$$ portable speaker for just £3 / $6? Left me show you how.

Lets get real here, you are not going to save lots of money you can probably buy a portable speaker, for you iphone or android phone direct from china for £6 / $12, but this way you get to save a trip to the dump, and get some satisfaction.

Old Speaker + £3 = Disco

Make a Portable Speaker with PAM8403 Amplifier - Ingredients

You will need the following ingredients:

  • An old speaker (4, 6 or 8 ohm) lower ohms = more volume.
  • Some wire (door bell, lead from old adaptor. . . )
  • Battery Holder to hold 3 x AA or 3x AAA batteries  
  • PAM8403 amplifier board
  • A drill 
  • screw driver
  • Soldering iron
  • solder
I have gone in to detail regarding the battery holder and the PAM8403 amplifier below.

Make a Portable Speaker with PAM8403 Amplifier - The Amplifier

You can buy the vanilla PAM8403 board on ebay for next to nothing but for a few £/$ more you could get hold of a blue tooth variant. This is useful if you want to use a phone without the 3.5mm jack socket.

There also variants with a volume control, and a smoothing capacitor. This may be worth getting if you do not have a spare capacitor

Bluetooth . . . . . volume control . . . . . or vanilla (normal) the choice to yours.

Make a Portable Speaker with PAM8403 Amplifier - Power Source

The amplifier run on a any voltage between 2.5V and 5.0V. This means you can power it with:

  • 3 x AA batteries
  • 3 x AAA batteries
  • USB power lead from PC or Wall Adaptor
  • 1 x 18650 Battery
  • A USB power bank
I have tried with a USB power lead, and then 3 x AA batteries both worked very well. 

The amp have two channels (left and right) and as far as I know you have to use both channels. You cannot splice the two channels together to make one. 

Make a Portable Speaker with PAM8403 Amplifier - How To

So the old speaker I have had a tweeter (small high frequency speaker) and woofer / midrange speaker. I used one "channel" from the amop for each. I cant remember which way around I put them. 

You will need to remove the cross over if there is one, save the capacitors for re-use.

In order to do this you will need to open up the speaker and, take a wire from either the woofer or the tweeter, you may find that you have a cross over unit in there, you will need to by-pass this so you can create two separate channels. Keep the cross over and carefully remove one of the capacitors for reuse, in a moment. You will need to solder this in to the positive wire of the tweeter. Like this:

Adding a capacitor as above will improve sound quality.

I first tried the amp and speaker together without this capacitor and the tweeter sounded distorted. However, after adding the capacitor all was well. 

The amplifier is tiny. . . note pinky (little finger) for scale.

Next up we need to start soldering all the bits together, if you do not have a soldering iron just buy one. They are useful for all sort of mending and fixing and making. As you can see the PAM8403 amplifier is tiny. And this makes for fiddly soldering, you can only use thin wire as the holes are too small for thick wire. 

Wiring is simple. . .but fiddly!

So for simplicity I house the wiring in a surface mounted junction box on the rear of the seapker, I had one of these spare in the garage. But you could actually just put all of the wires inside the speaker if you wanted to. Although it would be more fiddly to work on. 

3 x AA Battery Holder - £1.99

This cheap battery holder from ebay has a built in switch (counter sunk). I screwed it on to the rear of the speaker. With 3xAA batteries in side in produced 4.5V, good quality rechargeable batteries are preferable to disposable, as they hold a higher charge for longer, so voltage stays are close to the optimum (5V) as possible. 

Toggle switch. . . if you like.

I also added a toggle switch that I had as it is a nicer switch to use, than the one on the battery holder. You can also use a piece of cord, rope or strapping as a carry handle. 

Carry Handle

Make a Portable Speaker with PAM8403 Amplifier - Performance 

The sound level of the finished speaker (4 ohms / 4.5V ) is approximately 60 - 70 decibels. You cannot really have a normal conversation in the same room. As a 35+ year old man, I find it unpleasantly load at full volume.

There is quite a lot of midrange and high pitch sound, and perhaps some more bass would be a good, but overall for a piece of hardware that cost 99p, and is the size or a postage stamp it is amazing . . almost alchemy in terms of its performance. 

This is a fun, low cost project that I have enjoyed doing, and I would urge you to do the same if you require a speaker of this type rather than buying some other hard to recycle item from china.

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Thursday, 13 July 2017

Living with iOS 9.3.5 on an iPhone 4S

Living with iOS 9.3.5 on an iPhone 4S  - Intro

I have been avoiding upgrading my iOS since iOS 7. However, on wednesday night I drank too much red wine and upgraded, because an app I wanted to use requires iOS 9 or higher.

What a mistake to make. My snappy adequately fast phone was rendered sluggish and virtually useless. So what can I do?

Living with iOS 9.3.5 on an iPhone 4S  - Down-Grade - NO WAY

Apple must know that older devices will not run there newer iOS properly, and hope that the performance of iOS 9 on older devices will force people to upgrade. For this reason they do not offer a way to downgrade your iOS. 

There is one exception, and that is 6.1.3 which is still "signed" for use on the iPhone 4 (not 4S). There is 3rd party software avaiable to do this, if you have iOS 9.3.4, but not for iOS 9.3.5.

So this is impossible for 9.3.5.

Living with iOS 9.3.5 on an iPhone 4S  - Jail-Break - NOOOO WAY

This is also not possible, iOS 9.3.5 is not jail-break-able.

Living with iOS 9.3.5 on an iPhone 4S  - Re-Install and Performance Mods - WORTH A SHOT

This is the only way left for people, and I think by following the below steps you can claw back the usability of you iphone 4S.

9.3.5 Reinstall

  1. Back-Up Your Iphone (Use iTunes)
  2. Reset (Settings > General) Choose (Erase All Content and Settings) 
  3. Restore from Back Up when Done.
Note: This freed up a lot of storage space for me. Despite having most the same apps and music on the phone after restore. Perhaps the old iOS is not deleted from the phone when it is upgraded?

9.3.5 Performance Mods

Do the following:
  1. Turn Off Animations (Settings > General >Accessibility)
  2. Turn Off Transparency (Settings > General >Accessibility)
  3. Turn Off Back Ground App Refresh (Settings > General)
  4. Enable Low Power Mode (Settings > Battery)
  5. Delete All Unwanted Apps (Hold Down Any App Icon Until Wobble)

Living with iOS 9.3.5 on an iPhone 4S  - Conclusions

APPLE! It should not be like this, serve the customer please. If I want to install Windows 3.1 on my PC I can. . . . this means I do not have to send my old PC to india, for kids to dismantle, and go to early graves with lead poisoning. . . there is a moral element here!

Every time you make a new iphone there is also a carbon cost, it is no good prattling on about how considerate you are in you CSR reporting if your belligerent attitude towards legacy hardware is causing mountains of E-Waste, and unnecessary Carbon Emissions. You know global warming, that thing that Trump Ignores. . . but then he is a pretty good guy after all.   

Illustrator Devon

Tuesday, 11 July 2017

Daphon GA-1 Amplifier Review

Daphon GA-1 Amplifier Review - Intro

WHo wants a new blue tooth portable speaker when you can use a chunky black box, attached to your phone with a cable? I appreciate that this is a guitar amp, but I also thought it might be good for playing music through. . . . .turns out NOT. It is not even a very good amp, and yes I am considering the fact it is small and runs on batteries.

Daphon GA-1 Amplifier Review
A nice looking amp with a quality feel. . . . 

Daphon GA-1 Amplifier Review - Battery

This GA-1 takes a 9v power pack (LR6) what a faff that is , why not 6 xAA? That would be so much cheaper and easier. So that is a really annoying feature. Considering the amps performance (low) then you need to keep the battery in prime condition to deliver good sound, otherwise more distortion, and there is PLENTY of that any way.

Daphon GA-1 Amplifier Review BAttery
Really? That is the best battery option you could think of?

Daphon GA-1 Amplifier Review - Sound Quality

Terrible. There is something to be said for it small size, and if you are playing in your bedroom or maybe at a BBQ in the woods. . . . but the sound quality is so so poor, its hardly worth having. Using it a speaker for say music from an iphone is a terrible idea, as the sound distorts at an incredibly low volume. 

The Insides let this amp down. . .badly

Daphon GA-1 Amplifier Review - Insides

Inside the amp we see the board is centered around a panasonic (AN7142) 0.9W chip. This is well below the advertised 2W output, or leagues away from 5W max output touted.

Now I am not a electronic guy, but you can get amp chips that support 5W. So what have they done in there? Whatever they are doing it certainly looks as though the internals could be better.

A low power chip may be to blame for the terrible sound?

Daphon GA-1 Amplifier Review - Manufacturers Blurb

This is the blurb straight from daphon:

Portable Performance Amp

A perfect beginner guitar amp or a busker's best friend. Because of it's battery power you can have amplification wherever you are. The amp has the capacity to produce decent volume and you have control over your sound through tone control. Flick the drive button for a crunchy overdrive. Also suitable for microphones, though an impedance transformer is recommend for best performance.

Hours of Fun on a Single Battery

Runs on a single 9 volt battery (the rectangle type) that can last many hours depending on volume, can also be powered by a 9V ac adapter. The amp is 20cm / 16cm / 8cm in size and a headphone output is included for silent playing.

Music On-The-Go

Also a great portable music speaker. Just plug in your Mp3, Ipod or Discman via the input and you can have access to music wherever you go.

Daphon GA-1 Amplifier Review - Dimensions

Dimensions: 20cm x 16cm x 8cm
Weight: 1.2kg
Maximum power output: 5W
RMS power output: 2W

Daphon GA-1 Amplifier Review - Conclusions

A well built case a solid feeling controls, let down by very poor quality internals.

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Thursday, 29 June 2017

Schwalbe Dirty Harry BMX Tire Review

Schwalbe Dirty Harry BMX Tire Review - Intro

These are a cheap BMX tire from Schwalbe. However, do not be fooled by the price, this is an excellent tire that could be used on folding bikes, kids bikes as well as BMXs and have an excellent building quality and a good multipurpose grip. It comes in 20" (406) variant only, and is 1.95" wide.

Schwalbe Dirty Harry
Not Just for BMX

Schwalbe Dirty Harry BMX Tire Review - Grip

The tread pattern is ideal suited to street riding, loose gravel riding, and dry dirt. Where it quickly comes undone is claggy mud, where the closed block tread pattern quickly clogs. The tread pattern is also quite shallow, this is advantageous in that the "knobs" do not flex when under load but a disadvantage as they clog more readily. 

Schwalbe Dirty Harry
Tread Pattern Looks Flash and is Good for All Except Thick Mud

The rubber compound is SBC (Schwalbe Basic Compound) as used on early Big Apple Tires and is perfectly adequate, although not as good as some of their high end compounds. 

Schwalbe Dirty Harry BMX Tire Review - Build Quality 

These are a moderately high quality tire. But is has one blinding feature that most other BMX tires do not have, a kevlar puncture protection belt (Kevlar Guard). This is an excellent feature, and will stop punctures from just about anything, except hawthorns. 

Side View

The TPI is s little low if you want to carry large loads, but for normal riding is is very good. These have a soft feel when riding when compared to a very high TPI tire such as the Eclat Ridgestone.

Tread Deatil

Schwalbe Dirty Harry BMX Tire Review - Conclusions

A cheap reliable tire form a quality brand, with excellent puncture protection. A tread pattern suitable for all sorts of surfaces. . . .whats not to like?

Thursday, 8 June 2017

Informal Tender or Sealed Bids - Buyer's Guide

Informal Tender or Sealed Bids - Buyer's Guide - Intro

I am not an expert. But we have recently bid on a property using the Informal Tender or Sealed Bids process, and here are some observations which may be useful to you.

Informal Tender or Sealed Bids - The Property's Price

This is set by the estate agents to generate interest in the property, so it is likley to be below the actual value of the property.

You could complicate things here my trying to work out how much the property is worth. But the really the simple fact is, it is worth whatever you are willing to pay for it.

You don't really like it? - Bid 20% below  Price

You really want it? - Bid as much as you can afford*.

*I did look at some other similar properties nearby and this confirmed my suspicions that the property was under priced. For example if you are looking at a 3 bedroom terrace house for £180,000, and most property that are similar  sold recently for £220,000, then this will give you some idea of the level of bid that could be placed. Remember if you bid too much the mortgage company will find that the property is over-valued, and likley not lend you the money to buy it.

Informal Tender or Sealed Bids - How are the Bids Decided

Price would be a major factor with the buyer likley accepting the highest offer.

However, if to similar offers are received, then the buyer will likley choose the offer that which does not rely on chains or borrowing.

A chain free cash buyer would be most favourable, although I have read on line that cash buyers are not always the first to be picked.

Informal Tender or Sealed Bids - How to Bid

Ask the estate agent for a Informal Tender form or proforma, for you to fill out. If they do not have one then include the following information in a letter:

  • Title - Subject to Contract Informal Tender
  • For - The Address of House you wish to Buy
  • Your Name (s)
  • Your Address & Other Contact Details 
  • Is your offer and ability to proceed dependant on another property? Yes or No
  • If yes give details. 
  • Level of borrow you anticipate.
  • State of agreement regarding borrowing i.e. Agreement in Principal. 
  • Name of your Solicitors
  • Other things you think might be relevant. 

Informal Tender or Sealed Bids - When to Bid

You are hopefully delivering a envelope or an email to your estate agents.. . . . . . 

If the people running the tender are less than honest then it does not matter when you submit you bid, as the process is rigged. In this instance it may be advantageous to submit your tender at the last minute, so as to give the organiser less time to react.

If the people running the tender are honest, then nobody will see you bid other than the honest organiser and the vendor, so it does not really matter when you submit your bid.

Informal Tender or Sealed Bids - Can You Bid more than Once?

Yes, just submit a revised offer if you think you may have bid too much or too little.

Informal Tender or Sealed Bids - Have You "Won"?

You will normally find out within 1 or 2 weeks after the closing dates for bids. It may be that if you are the second best bidder, and the first best bidder withdraws then you might be in with a chance.

This is was the case when we bid, we were "significantly lower" than the winning bid, but for what ever reason they pulled out, and we are now buying the house! 

Friday, 26 May 2017

L1e-A Type Approval - Missed Opportunities

1 - L1e-A Type Approval - Missed Opportunities - Intro

The L1e-A class of vehicle is at at present described in European Directive 168/2013, at the moment there is no way of obtaining UK type approval for this vehicle. If you built a 15 mph 1000w ebike it would need to undergo the same inspection process as a Motor Bike.

But for now let us imagine that the DVSA had the resources to publish a list of requirements. If they followed the requirements set out in European Directive 168/2013, then the below list (Chapter 2) would be required, and uptake of the L1e-A vehicle class would be minimal. 

If we are to release to full environmental benefits of electrically assisted pedal cycles then we must allow a higher power rating under existing EAPC regulations, whilst maintaining current 15mph speed limit. 

If one has to tax and insure these higher powered, but low speed (15mph) vehicles what is the incentive in operating one? One may as-well opt for a "real" motor bike or a car.

In my various emails shared with the Department for Transport (Chapter 4) no reason for the current 250w limit has been given, the USA have a 750w limit which has been in use for over a decade. 

In short this could be a very useful, zero emission, transport solution. We need to clean up our air, we need to reduce our carbon emissions. 1000w 15mph EBikes and ETrikes could take over many of the jobs that Small Vans and Car currently do in our cities. 

Passengers . . .
. . . post. . . .
. . .  or freight.
Most of these heavier cycles are popular in the "low countries" such as Belgium and Holland. In the hilly UK, if these pedal powered vehicles are to be success then we will need a 1000w power limit on an assisting electric motor.  

2 - L1e-A Type Approval - Missed Opportunities - Requirements

L1e-A - Horn

You will not need am audible warning device. AKA a Horn.

L1e-A - Brakes

According to UNECE Reg. 78 unless the vehicle weighs less than 35kg. In which case normal bike brakes will be OK.

Rim widths must be kept under 45mm to avoid stopping distance requirements.

L1e-A - Endurance

Needs to be able to last for 5 years. Which bits this applies to I do not know, likley the frame I should think. 

L1e-A - Lights and Signals

A headlamp, a side reflectors, pedal reflectors. Headlights can be switched automatically or manually. No rear light is required.

This is rather silly. A rea light is one of the most important safety features on a bicycle. . . . the mind boggles.

L1e-A - Saddle

A normal bicycle saddle.

L1e-A - Tires

Normal bike tires provide loaded weight is below 150kg, and the tires are less than 67mm in width. This translates to 2.35" cycle tires being OK, which is pretty wide. 

L1e-A - Anti Tamper

The vehicle user should not be able to alter the vehicle speed above 15mph, with (i am guessing) an off road switch or similar.

L1e-A - Vehicle structure integrity

Must conform with EN 14764:2005. This is a bicycle standard realting to "City and trekking bicycles." So if you are converting a modern bike of the correct type then it should comply. However, this standard does not apply to:

"It does not apply to mountain bicycles and racing bicycles, tradesman's delivery bicycles, recumbent bicycles, tandems and bicycles designed and equipped for use in sanctioned competitive events."

L1e-A -Passenger handholds and footrests

These are not required. However this would suggest passengers are allowed. . . 

L1e-A - Registration Plate / Number Plate

10cm by 17,5cm space is required for mounting. This is annoying. This is large un-aerodynamic thing to fit on to a bicycle. 

L1e-A - Kick Stand

Yes you need one of these. A kick stand, or two foot stand for example. 

L1e-A - Propulsion Unit performance

This is a little complex, and will depend on the type of system. If a pedal assistance system then there are standards to be met (EN 15194:2009 &  UNECE Reg. No 8)

L1e-A -Electric energy consumption and electric range

There are no minimum range requirements. 

3 - L1e-A Type Approval - Missed Opportunities - - Conclusions

One of the great joys of owning a ebike is the lack of legislative burdens. No tax, no insurance, no requirement to wear a helmet. . . . 

The L1e - A category has the potential to revolutionise inner city transport if implemented correctly and sensitively. But if regulators are too heavy handed this form of vehicle will be relegated to an obscure and underutilized form of transport. 

4 - Type Approval Requirements L1e-A - Letters to DfT

I have had various contacts with the the Department for Transport. I would rather see this L1e-A bracket included under EAPC regulations.

Letter 1

An initial enquiry, brought boiler plate response. So . . . my response.

I think in the days before the world wide web, the response may well have been a useful one. But it is repetition of information that I have already read, and already have access to. It is all very well to choose 250 watts as a maximum power rating, but I fear this figure has been chosen at random with no true understanding how an electric motor works.

How will this be enforced? – We have a enforcement system that measures speed, not power.

Practicality? – Would you place a power limit on a Tractor?

Worthy Contribution? – A moderately fit rider can produce 800w power when cycling. 250w as an addition is rather small.

I summary I am trying to investigate why this 250w figure has been chosen. I would like to think there was some science behind it somewhere. . . . but I have a strong suspicion it was plucked from the air.

DfT response to Enquiry on why current limit is 250w.

Directive 2002/24 made type approval compulsory for all two wheeled motor vehicles,  except powered cycles not exceeding 250 watts. 
Unfortunately we have no detailed information on why that threshold was chosen. It may  have come from a prior threshold in an EU country where such cycles were common eg  Netherlands.

Letter 2 - Higher Power for Low Speed EBikes 

My Letter - Enquiring About Power Increase

Now that we are leaving the EU could we open a dialog on how best to increase max allowable power on pedal assisted EVs? To be clear 15mph speed limit would be maintained, with increased assistance level and torque.

Since our last communication we have heard that diesels will likely be banned in cities, and I think it is likely that electrical assisted vehicles can fill this gap.

With the price of electric cars and vans being inhibitive for most, I think now is the time to investigate this possible review of the EAPC regulations. Here are some links to some vehciles that would benefit from a change to the regulations: 

For Passengers

For Cargo

Surely this is worth looking at? We have an air quality and emissions mountain to climb in the next decade and this can only help. . . .

Dft Response to Increasing 

Thank you for your e-mail of 27 April concerning electrically assisted pedal  cycles (EAPCs). I have been asked to respond as I work in the Department  for Transport’s cycle policy team and lead on EAPCs.

As we are currently in the pre-election period, known as purdah, new policy  decisions cannot be taken until after 8 June when a new Government will  have been elected.

You may be aware that prior to the beginning of the purdah period detailed  guidance on compliance issues affecting certain EAPCs was published on the  Department for Transport’s website. For ease of reference here is a link to  the guidance.

My response to This

Thank you very much for you informative response. I had seen a draft of your linked document last year, I am worried that if these slow, low powered cycles are grouped with motor vehicles that the added administrative burdens will prevent their uptake.

I have recently read that there is a directive 168/2013 that introduces the category L1e-A for type approval. That is a 15mph top speed but with a 1000w power allowance.

This is exactly the type of bicycle I think that would prove useful for passenger and load carrying, and would provide a real alternative to cars and vans. Especially in hilly areas, were the current 250w allowance does not contribute meaningfully.

These types of cycle would also allow individuals and businesses to opt for zero emissions transport at a fraction of the cost of an electric car. This would accelerate the inner city air quality improvements required of the UK, whilst adding to the fitness and wellbeing of those using the cycles.

I believe that the DfT are updating type approval regulations at present, I would ask that the L1e-A category is merged with the EAPC regulations. I am of the opinion that attempts to classify these cycles as motor vehicles would severely restrict there up take, and thus limit the myriad of positive effects that they would bring for those using them, and air quality.

Finally, it is very difficult to enforce a system based on power ratings, at present our enforcement system favours speed as an enforcement mechanism, which most police can measure easily. If a bicycle is limited to 15mph, then there is very little point in having any more than 1000w power, any more and it is surplus to requirements. 

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